Download - Hoạt động 3
Tit 67, 68 Bi 2
0
5
10
15
20
25
30
35
161164167170173
Gio n i S 10 Ban KHTNGio vin: Cao Vn Kin
CHNG V. THNG K
Tit 67:
Bi 1: CC KHI NIM M U
Ngy son: 02/ 03/ 2009
Lp: 10A1, A2
I.Mc tiu bi dy:
- Hc sinh nhn thc c tm quang trng ca thng k trong nhiu lnh vc hot ng ca con ngi.
- Hc sinh nm c khi nim: n v iu tra, du hiu iu tra, mu, mu s liu, kch thc mu v iu tra mu.
II.Chun b:
Mt bi bo lin quan n s liu thng k trong bi hc.
III.Phng php dy hc:
m thoi, vn p.
IV.Tin trnh bi dy v cc hot ng:
1. n nh lp:
2. Kim tra bi c:
3. Bi mi:
Hot ng 1: Cho hc sinh xem s liu thng k v tnh hnh tai nn ca Cc ng b Vit Nam t nm 2000 - 2005 ( Bo gio dc - thi i ).
Hot ng ca thy
Hot ng ca tr
Ni dung ghi bng
Hng ngy khi c mt t bo hay xem mt bn tin truyn hnh, ta thng bt gp cc con s thng k. Chng hn, theo thng k ca ban phng chng lt bo T., cn bo s 6 hi u thng 10 trn vo min Trung nc ta lm cht 41 ngi, 85.000 ngi nh b tc mi v sp , lm cho hng trm ngi b thng v hng nghn ngi b mt nh ca...
( Qua con s thng k thit hi trn, ta c kt lun g v cn bo s 6? (1)
( Cc bin php khn cp ca Chnh ph khc phc hu qu ngay sau khi cn bo i qua? (2)
((1): T phn tch cc s liu thng k trn, chng ta rt ra c cc tri thc t thng tin cha ng trong cc s liu trn.
((2): T phn tch s liu trn ngi ta a ra cc d bo v nhng quyt nh ng n.
* Thng k l g?
-Cn bo rt mnh.
-Sc tn ph d di.
-Hu qu li qu nng n cho ngi dn min Trung.
-H tr tin bc cho ngi cht, ngi b thng hoc ngi mt nh ca.
-H tr s lng thc, thc phm cn thit cho ngi gp nn.
-H tr s thuc men cn thit (y t).
-Pht biu
1.Thng k l g?
Thng k l khoa hc v phng php thu thp, t chc, trnh by, phn tch v x l s liu.
Hot ng 2
( Cc khi nim v du hiu iu tra, n v v gi tr ca du hiu iu tra c lm quen t lp 7.
V d: iu tra v s hc sinh trong mi lp trng THPT Bc L ngi ta n mt s lp v ghi s s mi lp nh sau: (bng)
*Du hiu iu tra y l g?
(iu tra v iu g)
*C bao nhiu lp c iu tra, v n v iu tra l g?
*Gi tr du hiu iu tra?
(s hc sinh mi lp)
+ Bng ghi s s hc sinh trn gi l bng s liu.
+ T v d trn ta c mt mu s liu cc lp { 10A1, 10A2, ..., 10A10}
* v d trn kch thc mu l bao nhiu? (s lp)
* v d trn ta c mu s liu nh th no?
+ Nu ta thc hin iu tra trn mi n v iu tra th iu tra gi l iu tra ton b. Nu ch iu tra trn mt mu gi l iu tra mu.
* v d trn iu tra gi l iu tra g? (iu tra mu hay iu tra ton b)
* v d trn nu ta thc hin iu tra ton b th phi iu tra nh th no?
+ iu tra ton b i khi khng kh thi v s lng n v iu tra qu nhiu, hoc v khi mun iu tra th ph hu n v iu tra.Do chng ta thng ch iu tra v phn tch x l trn mu s liu thu c.
-iu tra v s hc sinh mi lp
-C 10 lp c iu tra
-n v iu tra l 1 lp
-Lp 10A1: 48 hs
10A2: 45 hs... 10A10: 49 hs.
-Kch thc mu bng 10.
48 45 48 47 43
45 44 46 48 49
-V ch iu tra 10/30 lp nn l iu tra mu.
-Ghi s s ca c 30 lp trng THPT Bc L.
STT
Lp
S s
1
2
3
4
5
6
7
8
9
10
10A1
10A2
10A3
10A4
10A5
10A6
10A7
10A8
10A9
10A10
48
45
48
47
43
45
44
46
48
49
2.Mu s liu:
-Mt tp con hu hn cc n v iu tra gi l mt mu.
-S phn t ca mt mu c gi l kch thc mu.
-Cc gi tr ca du hiu thu c trn mu c gi l mt mu s liu (mi gi tr nh th cn c gi l mt s liu ca mu).
Hot ng 3
V d: iu tra v kim nh cht lng cc hp sa ca mt nh my ch bin sa bng cch m hp sa iu tra. C th m ton b hay khng?
( Khng th: v ph hu n v iu tra.
-Khng th m ton b cc hp sa v:
+ S lng m hp sa qu ln.
+ Khng ngi kim tra.
+ Sau khi kim tra xong s hp sa trn s khng bn c.
Hot ng 4 Pht phiu hc tp.
Phiu hc tp
Chn cu ng ri khoanh trn vo cu .
Cu1: Khi iu tra cc con trong mi gia nh ca mt khu chung c ngi ta thu c mu s liu sau:
23154
32121
a.Du hiu iu tra y l g?
A.S gia nh trong khu chung c.
B.S con trong mi gia nh.
C.S ngi trong mi gia nh.
D.S ngi trong khu chung c.
b.Kch thc mu l bao nhiu?
A. 5
B. 6
C. 4
D. 10
c.C bao nhiu gi tr khc nhau ca mu s liu trn?
A. 5
B. 6
C. 4
D. 10
Cu 2: iu tra v in nng tiu th trong mt thng (tnh theo kw/h) ca mt khu chung c X c 50 gia nh, ngi ta n 15 gia nh ghi v thu c mu s liu sau:
807536109110
60837195102
367813012096
a.C bao nhiu gia nh tiu th in trn 100 kw/h mt thng?
A. 3
B. 4
C. 5
D. 6
b. iu tra trn gi l iu tra g?
A. iu tra mu
B. iu tra ton b
V. Rt kinh nghim sau tit dy:
Tit 68, 69:
Bi 2 TRNH BY MT MU S LIU
Ngy son: 08/ 03/ 2009
Lp: 10A1, A2
1. MC TIU:
1 V kin thc:
c v hiu c ni dung mt bng phn b tn s - tn sut, bng phn b tn s ghp lp.
2 V k nng:
- Bit lp bng phn b tn s - tn sut t mu s liu ban u.
- Bit v biu tn s, tn sut hnh ct; biu tn sut hnh qut; ng gp khc tn s, tn sut th hin bng phn b tn s, tn sut th hin bng phn b tn s - tn sut ghp lp.
3 V t duy:
Hiu c biu hnh ct, hnh qut v ng gp khc ca tn sut.
Cn thn, chnh xc
II. CHUN B :
- Chun b cc biu bng
- Chun b cc hnh v v pht cho hc nsinh.
III. PHNG PHP DY HC:
Gi m, vn p.
IV. TIN TRNH BI HC
1. n nh lp:
2. Kim tra bi c:
3. Bi mi:
Tit 68
Hot ng 1: Trnh by bng phn b tn s - tn sut
Hot ng ca hc sinh
Hot ng ca gio vin
Ni dung ghi bng
Gi tr 30 c 10 ln
Gi tr 32 c 20 ln
Gi tr 34 c 30 ln
Gi tr 36 c 15 ln
.
Nng sut 30:
10
120
( 8,3 %
Nng sut 32:
20
120
( 16,7%
Nng sut 34:
30
120
( 25 %
Nng sut 36:
15
120
( 12,5 %
i
n
120
= fi
i
i
n
f
N
=
(
ii
nf.N
=
1,5% ( 400= 6
18% ( 400= 72
55
400
( 100 = 13,75
33
400
( 100 = 8,25
18
400
( 100 = 4,5
10
400
( 100 = 2,5
+Treo bng c cha v d 1
+ Mu s liu c tm gi tr khc nhau 30, 32, 34, 36, 38, 40, 42, 44
+ Mi gi tr xut hin bao nhiu ln?
+S ln xut hin ca mi gi tr trong mu s liu c gi l tn s
+ Treo (hoc chiu)bng c cha bng 1 sgk trang 162
+Tnh s phn trm s tha rung c nng sut 30, 32, 34, ..
+Cho hc sinh ln lt tnh tng gi tr
+120 = N gl kch thc mu
+S phn trm ngi ta gi l tn sut
+ Tng qut ta c cng thc nh th no?
+ Gi hc sinh pht biu bng li
+ Treo bng 2 sgk trang 162 (chiu bng) phn b tn s - tn sut ln my chiu
1) Trn hng tn s, ngi ta dnh mt ghi kch thc mu
2) C th vit bng tn s- tn sut dng ngang
Treo bng 3 trang163sgk:
Pht phiu cho hc sinh v cho hc sinh in nhng ch du chm vo. Gii thch ti sao?
Gi mt hc sinh ln bng ghi vo bng ph ngng ch cn trng v cho hc sinh nhn xt
1. Bng phn b tn s- tn sut
nh ngha: S ln xut hin ca mi gi tr trong mu s liu c gi l tn s ca gi tr
nh ngha tn sut:
Tn sut fi ca gi tr xi l t s gia tn s ni v kch thc mu N.
fi =
i
n
N
CH : (SGK)
Hot ng 2: Trnh by bng phn b tn s - tn sut ghp lp
[160; 162] c 6 ln
[163; 165] c 12 ln
.
6
36
( 100 ( 16,7%
12
36
( 100 ( 33,3%
10
36
( 100 ( 27,8%
+ Treo bng c cha v d 2 sgk
GV: trnh by mu s liu c gn gang sc tch, nt l khi c nhiu s liu, ta thc hin vic ghp cc s li thnh tng on bng nhau [160;162], [163;165], [166;168],..
+ Cho hc sinh m cc s liu.
+ Tn s ca mi lp l s hc sinh trong lp
+ Treo bng 4 trang 163 sgk
+ Bng phn b tn s lp ghp
+ Cho hc sinh b sung thm tn sut
+ Treo bng 5 trang 164sgk
+ Cho hc sinh b sung nhng ch ..
+ Bng 5 c gi l bng phn b tn s - tn sut ghp lp
+ ta c th ghp lp theo na khong sao cho mt bn phi ca na khong cng l mt bn tri ca na khong tip theo
[159,5;162,5), [162,5;165,5),
+ Treo bng 6 trang 164sgk
+ Cho hc sinh b sung ch
2. Bng phn b tn s- tn sut ghp lp
nh ngha:
Cng c:
+ Nhn li cho hc sinh bng phn b tn sut, tn s, bng phn b tn sut, tn s ghp lp.
Tit 69:
Hot ng 1:
Kim tra bi c:
Cn ln lt 40 qu cam (n v gram) ta c kt qu sau (mu s liu)
85868686868687878787878888888889
89898989898990909090909191919293
939393949494949494
Cu hi:
Hy lp bng phn b tn s - tn sut ghp lp gm 85-86, 87-88, 89-90, 91-92, 93-94?.
Tr li:
Lp
Tn s
Tn sut (%)
[85; 86]
[87; 88]
[89; 90]
[91; 92]
[93; 94]
6
9
11
4
10
15
22,5
27,5
10
25
N = 40
Hot ng 2: Gii thiu cc dng biu
+ Biu hnh ct l mt cch th hin bng phn b tn s (tn sut) ghp lp
GV: Biu hnh ct c cc trc to th hin nhng iu g, cc ct (hnh ch nht) th hin iu g?
Chiu slide 5
Vd: Xt bng phn b tn s bng 5
V hai ng vung gc
Trn ng thng nm ngang (dng lm trc s), ta nh du cc on thng xc nh lp, bt u t on [160,162] cho ti [172;174].
Ti mi on, ta dng ln mt ct hnh ch nht vi y l on , cn chiu cao bng tn s ca lp m on xc nh.
Chiu slide 6
Trng hp gia cc ct khng c khe h
Chiu slide 11
Chiu slide 7
+ M t cch xy dng ng gp khc
Ta v hai ng thng vung gc nhau. Trn ng thng nm ngang (dng lm trc s), ta nh du cc im A1, A2, A3, A4, A5, Ai l trung im ca on (hhoc na khong) xc nh lp th i (i=1,2,3,4,5). Ti mi im Ai dng on thng AiMi vung gc vi ng thng nm ngang v c di bng tn s lp th i; c th A1M1 = 6,, A5M5 = 3. V cc on thng A1M1, A2M2,, A5M5, ta c mt ng gp khc
0
2
4
6
8
10
12
14
161164167170173
Chiu slide 12
Chiu slide 8
+ M t cch xy dng biu tn sut hnh qut H5.4
Cch v nh sau: Lp th nht [160;162] chim 6/36 = 1/6 ( 16,7% ca kch thc mu. Do , hnh qut s chim 1/6 hnh trn. s o gc ca hnh qut l 1/6.360 = 600. tng t cho cc lp cn li.
+ Biu hnh ct v biu hnh qut cn c s dng rng ri trong vic minh ho cc s liu thng k cc tnh hung khc
HDTP1:Hc sinh p dng ln bng v biu tn sut hnh ct th hin bng 5.
0
5
10
15
20
25
30
35
160 162163 165166 168 169 171172 174
0
2
4
6
8
10
12
14
162 164163 165166 168 169 171172 174
HTP2: V ng gp khc th hin bng 6
0
2
4
6
8
10
12
14
159,5162,5165,5168,5171,5174,5
[163;165]
[166;168]
[169;171]
[172;174]
[160;162]
0
2
4
6
8
10
12
14
16
18
20
22
1 2 3 45 67 89 10
0
5
10
15
20
25
30
35
40
1 2 3 45 67 89 10
0
2
4
6
8
10
12
14
16
18
20
22
1.53.55.57.59.5
[3;4]
[5;6]
[7;8]
[9;10]
[1;2]
26,5
48,5
70,5
92,5114,5
136,5158,5
0
2
4
6
8
10
12
14
17
15141211
98
6532
25
20
15
10
5
0
Series2
0
5
10
15
20
25
948584
75746564555445
44
353425
3. Biu
[163;165]
[166;168]
[169;171]
[172;174]
[160;162]
a) Biu tn s, tn sut hnh ct
[3;4]
[5;6]
[7;8]
[9;10]
[1;2]
Biu tn s hnh ct
0
2
4
6
8
10
12
14
16
18
20
22
1 2 3 45 67 89 10
0
5
10
15
20
25
30
35
160 162163 165166 168 169 171172 174
b) ng gp khc tn s, tn sut.
0
5
10
15
20
25
30
35
161164167170173
0
2
4
6
8
10
12
14
161164167170173
0
5
10
15
20
25
30
35
40
1 2 3 45 67 89 10
0
2
4
6
8
10
12
14
16
18
20
22
1.53.55.57.59.5
0
2
4
6
8
10
12
14
162 164163 165166 168 169 171172 174
0
2
4
6
8
10
12
14
159,5162,5165,5168,5171,5174,5
c) Biu tn sut hnh qut
Ch : (SGK)
Hot ng 4: Rn luyn k nng
Mt ln kim tra ton ca mt lp gm 55 hc sinh, thng k im s nh sau:
im
0
1
2
3
4
5
6
7
8
9
10
S hs
0
3
3
5
4
12
10
8
7
1
2
a) Hy lp bng tn s-tn sut ghp lp gm 5 lp 1-2,3-4,5-6,7-8,9-10
b) V biu tn s - tn sut hnh ct, ng gp khc, hnh qut.
Gi mt hc sinh in vo bng tn s tn sut
Chia hc sinh lm bn nhm v phn v tng dng biu vo giy A4 (nu chiu c) hoc vo bng chun b sn v treo ln.
Biu tn s hnh ct
Biu tn sut hnh ct
ng gp khc
Biu tn sut hnh qut
lp
tn s
tn sut (%)
[1;2]
[3;4]
[5;6]
[7;8]
[9;10]
6
9
22
15
3
10,9
16,4
40
27,3
5,4
N = 55
4. Cng c tit dy:
- Cc dng biu : hnh ct, ng gp khc, hnh qut
- p dng:
Lp biu hnh ct tn s, tn sut, biu ng gp khc, hnh qut.
Trc nghim:
Trong mt gii bng hc sinh, ngi ta t chc mt cuc thi d on kt qu ca 25 trn u ng ch nht. Sau y l bng tn s _ tn sut ghp lp thu c:
Lp
Khong
Tn s
Tn sut
1
50-124
3
12%
2
125-199
5
29%
3
200-274
7
28%
4
275-349
*
20%
5
350-424
3
***
6
425-499
2
8%
N=**
1. Hy in v tr thch hp vo v tr *:
A. 5
B.10
C.15
D.25
2. Hy in v tr thch hp vo v tr **:
A. 100
B.50
C.25
D.Cha xc nh c
3. Hy in v tr thch hp vo v tr ***:
A. 6%
B.12%
C.24%
D.14%
p n: 1.A2.C
3.B
V. RT KINH NGHIM SAU TIT DY:
Tit 70:
LUYN TP TRNH BY MT MU S LIU
Ngy son: 08/ 03/ 2009
Lp: 10A1, A2
I. MC TIU BI DY
1. V kin thc
Cng c cc khi nim mu s liu, tn s, tn sut, tn sut ghp lp
V biu
2. V k nng
Lp biu tn s - tn sut ghp lp
V biu hnh ct, hnh qut
3. V t duy
Rn luyn kha nng phn tch, tng hp cc s liu
4. V thi
Cn thn, chnh xc
Nghim tc trong cng vic
II. CHUN B PHNG TIN DY HC
1.Thc tin: hc sinh hc ni dung bi 1 v bi 2
2. Phng tin
Hc sinh: Chun b bi tp 6, 7, 8 sgk nng cao trang 169 nh
Gio vin: Giy rki kh Ao, Bt x, computer, projecter
III. PHNG PHP DY HC
1.Gi m vn p khi trnh chiu
2. Luyn tp theo nhm di s hng dn ca gio vin
Chia lp thnh 3 nhm, mi nhm lm mt bi tp v trnh by vo giy rki vi thi gian d kin 10 pht
Mi nhm c i din trnh by bi gii trc lp d kin thi gian cho mi nhm trnh by 5 pht, cho hc sinh nhn xt bi trnh by vi thi gian l 3 pht sau mi nhm trnh by
Sau mi nhm trnh by gio vin nhn xt, trnh chiu ni dung bi dy
IV. TIN TRNH BI DY
1. n nh lp:
2. Kim tra bi c:
3. Bi mi:
Hot ng ca hc sinh
Hot ng ca gio vin
Ni dung ghi bng
Nhn giy, bt
Tin hnh lm bi vo giy rki
Phn nhm, pht giy, bt, phn nhim v
n c vic thc hin
Nhm 1 trnh by bi 6
Hc sinh nhn xt
Theo di
Nhn xt v trnh chiu
Bi 6:
a. Du hiu: Doanh thu ca ca hng trong mt thng. n v iu tra: Mt ca hng
b. Bng phn b tn s - tn sut ghp lp
Lp
Tn s
Tn sut (%)
[26,5;48,5)
[48,5;70,5)
[70,5;92,5)
[92,5;114,5)
[114,5;136,5)
[136,5;158,5)
[158,5;180,5)
2
8
12
12
8
7
1
4
16
24
24
16
14
2
N= 50
c. Biu tn s hnh ct
Nhm 2 trnh by bi 7
Hc sinh nhn xt
Theo di
Nhn xt v trnh chiu
Bi 7:
a. Du hiu: S cun phim m mt nh nhip nh dng trong thng trc . n v iu tra: Mt nh nhip nh nghip d
b. Bng phn b tn s ghp lp
Lp
Tn s
[0;2]
[3;5]
[6;8]
[9;11]
[12;14]
[15;17]
10
23
10
3
3
1
N = 50
c. Biu tn s hnh ct
Nhm 2 trnh by bi 8
Hc sinh nhn xt
Theo di
Nhn xt v trnh chiu
Bi 8:
a. Bng phn b tn s - tn sut ghp lp
Lp
Tn s
Tn sut(%)
[25;34]
[35;44]
[45;54]
[55;64]
[65;74]
[75;84]
[85;94]
3
5
6
5
4
3
4
10
17
20
17
13
10
13
N =30
b. Biu tn sut hnh ct
4. Cng c bi dy
Nu li tn s , tn sut ghp lp
Nhn mnh k nng v biu
Phn Trc nghim
Cu 1: in cc s vo ch trng (...) ct tn s v tn sut
Lp
Tn s
Tn sut(%)
[10;19]
[20;29]
[30;39]
[40;49]
[50;59]
[60;69]
[70;79]
[80;89]
[90;99]
1
14
...
73
42
...
9
4
2
...
7,82
11,73
40,78
...
7,26
5,02
...
1,11
N = 179
Cu 2: Cho bng phn b tn s - tn sut sau
Lp
Tn s
Tn sut(%)
[1;10]
[11;20]
[21;30]
...
5
29
21
...
6,25
36,25
26,25
.....
Kch thc mu N l:
a. N = 40 b. N = 60 c. N = 80 d. N = 100
V. RT KINH NGHIM SAU TIT DY:
Tit 71, 72:
Bi 3 CC S C TRNG CA MU S LIU
Ngy son: 25/ 03/ 2009
Lp: 10A1, A2
I.MC TIU: Gip hc sinh:
1. V kin thc: Nh c cng thc tnh cc s c trng ca mu s liu nh trung bnh, s trung v, mt, phng sai v lch chun v hiu c ngha ca cc s c trng ny.
2. V k nng: Bit cch tnh cc s trung bnh, s trung v, mt, phng sai, lch chun.
3. V t duy v thi :
- Rn luyn t duy lgc sng to. Bit quy l v quen.
- Rn luyn thi nghim tc, c tnh cn thn chnh xc trong qu trnh hc tp v thc hnh gii Ton.
II. CHUN B:
Hc sinh: Hc sinh n li kin thc thng k lp 7, bit c s trung bnh. Mt.
Gio vin: Chun b gio n dng c ging dy, SGK, my chiu
III. PHNG PHP DY HC:
Phng php m vn p thng qua cc hot ng iu khin t duy
IV. TIN TRNH BI GING:
1. n nh lp:
2. Kim tra bi c:
Chn 36 hs nam trng THPT v o chiu cao ca h, ta c mu s liu sau
160
161
161
162
162
162
163
163
163
164
164
164
164
165
165
165
165
165
166
166
166
166
167
167
168
168
168
168
169
169
170
171
171
172
172
174
Hy lp bng phn b tn s, tn sut
3 .Bi mi:
Tit 71
Hot ng ca Gio vin
Hot ng ca hc sinh
Ni dung
H 1: Phn nhm hot ng. Tnh s trung bnh ca mu s liu (Phiu hc tp)
Nhm 1, 3: Tnh s trung bnh ca mu s liu trong bng sau: S hc sinh ca mi lp 10 ca trng BL
Lp
10a
10b
10c
10d
10e
10g
Ss
47
50
48
49
46
45
Nhm 2, 4: im kim tra ca lp 10A c bn lp trng thng k li nh sau:
im
2
3
4
5
6
7
8
9
10
tn s
2
4
6
8
1
3
2
2
2
N=30
Hy tnh s im trung bnh ca mu s liu ca mu s liu trn
(Cng thc tnh s trung bnh hc lp 7)
+GV cho hc sinh nhn xt v rt ra cng thc tng qut
H 2: Tr li bng phn b tn s v tn sut ghp lp
Lp
Tn s
Tn sut
[160; 162]
[163; 165]
[166; 168]
[169; 171]
[172; 174]
6
12
10
5
3
16,7
33,3
27,8
13,9
8,3
N=36
+Yu cu hc sinh xc nh trung im ca tng on c ttrong bng trn [160; 162], [163; 165], [166; 168], [169; 171], [172; 174]
T GV a ra khi nim gi tr i din ca lp
Lp
Gi tr i din
Tn s
[160; 162]
[163; 165]
[166; 168]
[169; 171]
[172; 174]
161
164
167
170
173
6
12
10
5
3
N=36
Gv a ra cng thc tnh s trung bnh ca mu s liu ny
+ Yu cu hs vn dng tnhgi tr trung bnh ca mu s liu trong bng trn
+ V d 1(sgk)
+a ra ngha ca s trung bnh
H3: GV a ra v d v s trung bnh khng i din ng cho cc s liu ca mu
VD 2 sgk
+ Yu cu hs tnh s trung bnh v nhn xt
a ra s c trng khc thch hp hn l s trung v
H 4: Cng c khi nim s trung v (lm cho hs nhn thy tnh s trung v trc ht cn sp xp cc s liu trong mu theo th t tng dn)
+Yu cu hs tnh s trung v ca mu s liu trong v d 2
+GV cho hs c H2 v tr li yu cu ca v tnh s trung bnh ca mu s liu trn
Rt ra nhn xt (Khi s liu trong mu khng c s chnh lch qu ln th s trung bnh v s trung v xp x nhau)
H 5: GV a ra bng thng k v yu cu hs xc nh mt ca mu s liu bng tn s, tn sut
+Bng phn b o chiu cao ca 50 cy lim
Xi(m)
9
10
11
12
13
14
ni
6
7
10
11
8
8
50
(My chiu)
+ Hy tm mt ca bng phn b trn (hc sinh hc khi nim mt lp 7)
T suy ra kha nim mt
a ra v d 2 (sgk) rt ra ch mt mu s liu c th c nhiu mt
+ Hc sinh tnh s hc sinh trung bnh ca mi lp theo nhm hot ng
+Hc sinh lp cng thc tnh s trung bnh khi mu s liu cho dng mt bng tn s
+Cc nhm c i din nhn xt kt qu v a ra cng thc
+Hc sinh xc nh gi tr trung im ca mi on
+ Hs tnh theo cng thc
+ Hs tnh v nhn xt
+Hs tnh s trung v
+Hs nhn cu hi v tr li sau so snh s trung bnh v s trung v
+Hs ch ra mt v nhc li khi nim mt
I. S trung bnh:
Gi s c mt mu s liu kch thc N l {x1, x2, , xn }. S trung bnh ca mu s liu ny, k hiu l
x
12
...
N
xxx
x
N
+++
=
(1)
Hay
1
1
N
i
i
xx
N
=
=
Gi s mu s liu cho di dng mt bng phn b tn s
Gi tr
12
...
m
xxx
Tns
12
...
m
nnn
N
Khi :
1122
1
...
1
m
mm
ii
i
nxnxnx
xnx
NN
=
+++
==
trong ni l tn s ca s liu xi, (i=1, 2, ,m),
1
m
i
i
n
=
=N
Gi s mu s liu kch thc N cho di bng tn s ghp lp. Cc s liu c chia thnh m lp ng vi m on (m khong).
Trung im ca on (khong) ng vi lp th i l gi tr i din ca lp
Lp
Gi tr i din
Tn s
[a1; a2 ]
[a3; a4 ]
.
.
[a2m-1 ; a2m ]
x1
x2
.
.
. xm
n1
n1
.
.
nm
N=
1
m
i
i
n
=
Lp
Gi tr i din
Tn s
[a1; a2 )
[a2; a3 )
.
.
[am; am+1 )
x1
x2
.
.
. xm
n1
n1
.
.
nm
N=
1
m
i
i
n
=
1
1
m
ii
i
xnx
N
=
* ngha ca s trung bnh (sgk)
II.S trung v:
nh ngha (sgk)
Ch : Khi s liu trong mu s liu khng c s chnh lch qu ln th s trung bnh v s trung v xp x nhau
III.Mt:
Cho mt mu s liu di dng bng ph n b tn s. Gi tr c tn s ln nht c gi l mt ca mu s liu, k hiu M0
*Ch : Mt mu s liu c th c 1 hay nhiu mt
H Cng c: Nhm gip hs nh cng thc tnh s trung bnh ca mu s liu, s trung v, mt
BT: C 100 hs tham d k thi hs gii Ton (thang im 20). Kt qu c cho trong bng sau y
im
9
10
11
12
13
14
15
16
17
18
19
tn s
1
1
3
5
8
13
19
24
14
10
2
N=100
+ Tnh s trung bnh
+Tnh s trung v v mt ca mu s liu trn
Tit 72
Kim tra bi c
. im trung bnh tng mn hc ca 2 hs An v Bnh trong nm hc va qua c cho trong bng sau (My chiu)
MN
IM CA AN
IM CA BNH
Ton
Vt li
Ho hc
Sinh hc
Ng vn
Lch s
a l
Ting Anh
Th dc
Cng ngh
Gio dc cng dn
8
7,5
7,8
8,3
7
8
8,2
9
8
8,3
9
8,5
9,5
9,5
8,5
5
5,5
6
9
9
8,5
10
Tnh im trung bnh (khng k h s) ca tt c cc mn hc ca An v Bnh. Theo em bn no hc kh hn
Hot ng ca Gio vin
Hot ng ca Hc sinh
Ni dung
H 1: T cu hi kim tra bi c i vo khi nim phng sai v lch chun
S chnh lch, bin ng gia cc im ca An th t, ca Bnh th nhiu
Suy ra o mc chnh lch gia cc gi tr ca mu s liu so vi s trung bnh, ngi ta a ra 2 s c trng l phng sai v lch chun
GV i vo nh ngha, cng thc tnh phng sai v lch chun
H 2: Tnh phng sai v lch chun im cc mn hc ca An v Bnh
+Yu cu hs so snh
2
A
s
v
2
B
s
kt hp nhn xt trn v s hc lch ca 2 hs, rt ra nhn xt
T nu ngha ca phng sai v lch chun
H 3: GV a ra ch c th bin i cng thc (3) thnh cng thc (4) m vic p dng tnh phng sai v lch chun tin hn
+ Cho hs th li cng thc trn bng vic s dng my tnh tinh phng sai.
Yu cu hs phi tnh
1
N
i
i
x
=
,
2
1
N
i
i
x
=
. Sau tnh(4)
H 4: a ra bng phn b tn s v yu cu hs tnh phng sai T hnh thnh cng thc tnh phng sai
+Cho bng phn phi tn s: (S dng my chiu)
Bng phn phi thc nghim o chiu cao ca 50 cy lim
Xi(m)
9
10
11
12
13
14
ni
6
7
10
10
9
8
50
Tnh chiu cao trung bnh ca 50 cy lim
Tnh phng sai v lch chun
(Gi t cng thc (4) suy ra)
+GV hng dn hs mun tnh phng sai trc ht ta phi tnh:
1
m
ii
i
nx
=
,
2
1
m
ii
i
nx
=
Tnh (5)
+GV hng dn hs s dng my tnh tnh phng sai v lch chun
+Hs nm nh ngha v cng thc tnh phng sai v lch chun
+Hs p dng cng thc v tnh
2
0,309
A
s
v
0,556
A
s
2
2,764
B
s
v
1,663
B
s
+Hs nhn xt
22
BA
ss
>
Bnh hc lch Cc mn hn An
+Hs dng my tnh v tnh li
+Hs tnh chiu cao trung bnh
+Hs a ra cng thc tnh v dng my tnh tnh
+Hs tnh tng cng thc
6.97.1010.1110.129.138.14
50
x
+++++
=
=
6
1
ii
i
nx
=
=
EMBED Equation.DSMT4
6
2
1
ii
i
nx
=
IV. Phng sai v lch chun:
nh ngha:(sgk)
Cng thc tnh phng sai
2
s
v lch chun
s
(
)
(
)
2
2
1
2
1
1
1
N
i
i
N
i
i
sxx
N
sxx
N
=
=
=-
=-
(3)
ngha ca phng sai v lch chun:
Phng sai v lch chun o mc phn tn cc s liu trong mu quanh s trung bnh. Phng sai v lch chn cng ln th phn tn cng ln
*Ch : C th bin i cng thc (3) thnh
2
22
2
11
11
NN
ii
ii
sxx
NN
==
=-
(4)
.
+Nu s liu c cho di bng phn b tn s th phng sai c tnh bi cng thc:
2
22
2
11
11
mm
iiii
ii
snxnx
NN
==
=-
(5)
VD: Bng phn phi thc nghim o chiu cao ca 50 cy lim
Xi(m)
9
10
11
12
13
14
ni
6
7
10
10
9
8
50
1) Tnh chiu cao trung bnh ca 50 cy lim
2) Tnh phng sai v lch chun
Gii:
1.
6.97.1010.1110.129.138.14
50
x
+++++
=
=
2.
6
1
ii
i
nx
=
=
6
2
1
ii
i
nx
=
=
2
66
22
2
11
11
5050
iiii
ii
snxnx
==
=-
4. Cng c: Rn luyn cho hs s dng my tnh tnh phng sai v lch chun
BT: C 100 hs tham d k thi hs gii Ton (thang im 20). Kt qu c cho trong bng sau y
im
9
10
11
12
13
14
15
16
17
18
19
tn s
1
1
3
5
8
13
19
24
14
10
2
N=100
+ Tnh s trung bnh
+ Tnh s trung v v mt ca mu s liu trn
+ Tnh phng sai v lch chun
V. RT KINH NGHIM SAU TIT DY:
Tit 73:
LUYN TP
Ngy son:
Lp: 10A1, A2
I. MC TIU:
1. V kin thc :
Nm cc cng thc tnh cc s c trng ca mu s liu
2. V k nng :
Rn luyn k nng tnh cc s trung bnh, s trung v, mt, phng sai, lch chun
S dng my tnh b ti
3. V t duy v thi :
- Hc sinh nm cc nh ngha, cng thc.
- Thy c ngha thc tin ca bi hc
- Chun b my tnh b ti( thng dng v casio Fx 500 Ms )
II. CHUN B CA GV V HS:
Gio vin: Chun b dng c hc tp, phiu hc tp v cc bi tp.
Hc sinh: Hc bi c v lm cc bi tp trong SGK
III. PHNG PHP DY HC:
Gii quyt tnh hung c vn
IV. TIN TRNH BI HC:
1. n nh lp:
2. Kim tra bi c
3. Bi tp luyn tp
Hot ng ca gio vin
Hot ng ca hc sinh
Ni dung ghi bng
Hot ng 1: T chc, hng dn hc sinh gii bi tp 1.
- a bng ph c bi
- Phn lp ra 4 nhm:
+ Nhm 1, 2 : gii cu a
+ Nhm 3, 4 gii cu b
- Nhn v chnh xc ho kt qu ca cc nhm
- a ra li gii cho c lp
*Cu hi:
+ Cng thc tnh s trung bnh, s trung v, phng sai v lch chun
+ Dng s liu bi cho?
+ Khi tnh s trung v ta cn lm g?
Hot ng 1:
- c v nu thc mc v bi
- nh hng cch gii bi ton
- c lp tin hnh gii ton theo tng nhm
- Thng bo kt qa cho gio vin khi hon thnh nhim v
- Chnh xc ho kt qu(ghi li gii ca bi ton)
*
+ Hc sinh nu cc cng thc.
+ Mu s liu kch thc N
+ Sp xp li s li theo th t khng gim
Bi tp 1: S liu sau y cho ta li ( quy trn) hng thng ca mt ca hng trong nm 2005. n v l triu ng
Thng
1
2
3
4
5
6
7
8
9
10
11
12
Li
12
15
18
13
13
16
18
14
15
17
20
17
a Tm s trung bnh, s trung v.
b Tm phng sai v lch chun.
Gii:
A S trung bnh
x
=
EMBED Equation.DSMT4
121518131316181415172017
12
+++++++++++
15,67
x
triu ng
S trung v Me =(15+16):2 =15,5 triu ng
b Phng sai
12
22
1
1
()5,39
12
i
i
sXX
=
=-
lch chun
2,32
s
triu ng
Hot ng2:T chc, hng dn hc sinh gii bi tp 2
- a bng ph c bi
- Chuyn i cc nhm vi cu hi: Nhm 1, 2 gii cu b: nhm 3, 4 gii cu a
Hot ng 2:
- Tin hnh hon ton nh hot ng 1 nhng ch yu cu mi nhm gi thay i
- Thng bo kt qu vi gio vin, nu sai tnh ton li
Bi tp 2:
Mt ca hng vt liu xy dng thng k s bao xi mng bn ra trong 23 ngy cui nm 2005. Kt qu nh sau:
47 54 43 50 61 36 65 54 50 43 63 59 36 45 45 33 53 67 21 45 50 36 58
a Tm s trung bnh, s trung v
b Tm phng sai v lch chun
Gii:
p s
a/
EMBED Equation.DSMT4
EMBED Equation.DSMT4
48,39
50
e
x
M
=
b/
2
121,98
11,04
s
s
Hot ng 3: T chc, hng dn hc sinh gii bi tp 3
+ C lp tin hnh gii bi tp 3 c lp tng c nhn
+ Gio vin hng dn nu c yu cu t hc sinh
+ Thu nhn kt qu sm nht t 2 n 6 hc sinh gii xong u tin
+ Nu hng gii v chnh xc ho li gii
+ Nu ngha thc t
Hot ng 3
+ Hc sinh c lp nghin cu yu cu bi ton, hng gii quyt bi ton
+ Tnh ton c th
+ Thng bo kt qu cho gio vin
+ Chnh xc ho li gii
Bi tp 3 :Trn 2 con ng A v B, trm kim sot ghi li tc (km/h) ca 30 chic t trn mi con ng nh sau :
- Con ng A: 60 65 70 68 62 75 80 83 82 69 73 75 85 72 67 88 90 85 72 63 75 76 85 84 70 61 60 65 73 76 .
- Con ng B: 76 64 58 82 72 70 68 75 63 67 70 74 79 80 73 75 71 68 72 79 80 63 62 71 70 74 69 60 63
a. Tm s trung bnh, s trung v, phng sai v lch chun ca tc t trn mi con ng A, B
b. Theo em th xe chy trn con ng no an ton hn
Gii :
a. Trn con ng A
3,63/;73/
e
xkmhkmh
M
=
2
74,77;8,65
ss
Trn con ng B
70,7/;71/
e
xkmhkmh
M
=
2
38,21;6,18
ss
b Nhn chung, li xe trn con ng B an ton hn trn con ng A v vn tc trung bnh ca t trn con ng B nh hn trn con ng A v lch chun ca t trn con ng B cng nh hn trn con ng A
Hot ng 4
Gio vin a bng ph c bi tp 4
+ T chc cho hc sinh c lp tin hnh gii
Xem y l bi ton gii nhanh, chm im cho 5 hc sinh gii nhanh nht
+Chnh xc ho bi gii
Hot ng 4:
+ Hc sinh nghin cu bi, nh hng cch gii
+ Phn bit dng mu s liu(cho bng.ghp)
+ Thng bo kt qu cho gio vin nu gii nhanh
+ Chnh xc ho bi gii
Bi tp 4:
Mt ca hng n ghi li s tin( nghn ng) m mi khch tr cho ca hng . Cc s liu c trnh by bng tn s ghp lp sau :
Lp
Tn s
[0;99]
[100; 199]
[200;299]
[300;399]
[400;499]
20
80
70
30
10
N=210
Tnh s trung bnh v lch chun
Kt qu: S trung bnh l 216,7 lch chun l 99,2.
Hot ng 5: Cng c
+ Cch tnh cc s c trng ca mu s chung
+Khi tnh s trung v phi sp xp li nu cha sp xp
4. Cng c:
Nhc li cc dng bi tp v h thng kin thc:
V. RT KINH NGHIM SAU TIT DY:
Tit 74:
CU HI V BI TP N TP CHNG V
Ngy son:
Lp: 10A1, A2
I. MC TIU:
1. Kin thc:
Cng c cc khi nim v tn s, tn sut, bng phn b v tn s, tn sut, biu tn s, tn sut.
Khc su cc cng thc tnh s liu c trng ca mu s liu.
Hiu c cc con s ny.
2. K nng:
- Tnh cc s liu c trng ca mu s liu
- Bit trnh by mu s liu di dng bng phn b tn s, tn sut; bng phn b tn s, tn sut ghp lp.
- Bit v biu .
3. T duy v thi :
- ng dng vo thc t, p dng trong hc tp, trong trng hc.
- Lin h vo thc t, trong i sng.
- Cn thn, chnh xc. Nghim tc trong cng vic.
II. CHUN B CA GV V HS:
Gio vin: Bng ph, phiu hc tp, my tnh b ti.
Hc sinh: Bi tp nh
Nm c cc cng thc tnh ton.
III. PHNG PHP DY HC:
Gi m, vn p,gii quyt vn .
Lm vic theo nhm.
IV. TIN TRNH BI HC:
A. Cc tnh hung hc tp:
Hot ng 1: Kim tra cc cng thc.
Hot ng 2: Trc nghim l thuyt.
Hot ng 3: Tnh ton cc s liu c trng.
Hot ng 4: Gii ton trn my tnh b ti.
B. Tin trnh bi hc:
Kim tra bi c:
Hot ng 1:
Hot ng gio vin
hot ng hc sinh
Ni dung ghi bng
H1: Nu cc cng thc tnh s trung bnh, s trung v, phng sai, lch chun i vi mu s liu cho bng bng phn b tn s ghp lp?
Yu cu hc sinh nu r cc cng thc.
Gio vin nhn xt, nh gi
- Hc sinh trnh by cc cng thc.
x
; S2; Me; S
Mu s liu cho bng bng tn s ghp lp:
1
1
m
ii
i
xnx
N
=
=
EMBED Equation.DSMT4
S2
22
2
11
11
()
mm
iiii
ii
nxnx
NN
==
=-
N l: Me l s liu ng th
N+1
2
N chn: l trung bnh cng ca hai s liu ng th
N
2
v
N
1
2
+
S =
22
2
11
11
()
mm
iiii
ii
nxnx
NN
==
-
B) Bi mi:
Hot ng 2: Trc nghim l thuyt thng qua bi tp 16, 17
- Hc sinh chun b trong 2 pht, ng ti ch tr li.
Chn C
Bi 16:
Chn C
Bi 17:
Chn C
Hot ng 3: Tnh ton cc s liu c trng trn mu s liu:
Phn nhm, giao nhim v cho hc sinh
6 nhm:
- 2 nhm lm bi 18 (1, 2)
- 2 nhm lm bi 20 (3, 4)
- 2 nhm lm bi 21 ( 5, 6)
Gi hc sinh lp bng phn b tn s ghp lp.
Ghi gi tr i din.
* i din nhm 1 trnh by, cc nhm cn li nhn xt.
Cho i din nhm trnh by
Gv cho i din nhm 5 ln trnh by
Lp bng
* Treo bng ph m hc sinh trnh by ln trc lp.
* Hc sinh lng nghe nhim v v thc hin theo yu cu
Nhm 3 trnh by bi.
i din nhm 5 ln trnh by
Bi 18:
Lp
gi tr i din
tn s
(27,5; 32,5)
(32,5; 37,5)
(37,5; 42,5)
(42,5; 47,5)
(47,5; 52,5)
30
35
40
45
50
18
76
200
100
6
N=400
EMBED Equation.DSMT4
x
= 40g
2
S
EMBED Equation.DSMT4
17g
S
4,12g
Bi 20:
a)
Tui
12
13
14
15
16
17
Tn s
2
2
1
4
2
5
18
19
20
21
22
23
25
5
2
2
2
1
1
1
N=30
b)
x
EMBED Equation.DSMT4
17,37
S
3,12
c)Me = 17
C hai mt : Mo =17 v Mo = 18
Bi 21:
Lp
Gi tr i din
tn s
(50; 60)
(60; 70)
(70; 80)
(80; 90)
(90; 100)
55
65
75
85
95
2
6
10
8
4
N=30
a)
x
EMBED Equation.DSMT4
77
b) S2
122,67
S
11,08
Hot ng 4:Gii ton trn my tnh b ti:
Hng dn tnh ton cc s c trng bng MTBT
Gv trnh by cc tnh
Ly bi 18 v bm kim tra kt qu.
Hc sinh quan st v thc hnh trn my
Hc sinh thc hnh
x
EMBED Equation.DSMT4
40g
S
4,17
S2
17
Dng my tnh Casio fx-570Ms
Hd: Vo ch thng k:
n Mode Mode 1
Nhp s liu:
x1 DT x2 DT ..
xn DT
Nhp mu s liu:
x1 Shift n1 ;DT
x2 Shift n2 ; DT
* Tnh
x
:
n: x1
Shift S-VAR 1 =
* Tnh lch chun S
n Shift S-VAR 2 =
* Tnh phng sai S2 ( ly bnh phng lch chun)
n x2 =
4. Cng c:
Nm cch tnh s liu c trng
Gii ton bng my tnh b ti.
C th ra mt s bi tp lm thm ( Lm bi tp sch bi tp)
Chun b tit sau kim tra 1 tit.
V. RT KINH NGHIM SAU TIT DY:
M1
180,5
M5
A2
M1
M4
M3
A4
A5
M2
A2
A1
A3
M5
M4
M1
M3
M2
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
A5
A4
A3
A1
EMBED MSGraph.Chart.8 \s
33.3%
16.7%
8.3%
27.8%
13.9%
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
EMBED MSGraph.Chart.8 \s
16.4%
10.9%
5.4%
40%
27.3%
PAGE
Trang1
T TON TIN TRNG THPT BC L
_1223584195.unknown
_1224063642.unknown
_1225420965.unknown
_1226681484.unknown
_1229863329.unknown
_1298052803.
_1298053742.
_1298053743.
_1298053740.
_1298053741.
_1298053739.
_1298052785.
_1298052802.
_1229863333.unknown
_1229863143.unknown
_1229863264.unknown
_1227098959.unknown
_1226678400.unknown
_1226681256.unknown
_1226681292.unknown
_1226681277.unknown
_1226678970.unknown
_1226681222.unknown
_1226678271.unknown
_1226678272.unknown
_1225421029.unknown
_1224887936.unknown
_1225420836.unknown
_1225420908.unknown
_1224888010.unknown
_1225392382.
_1225420509.unknown
_1225389561.
_1224887979.unknown
_1224830875.unknown
_1224886420.unknown
_1224887908.unknown
_1224886600.unknown
_1224886221.unknown
_1224829473.unknown
_1224830618.unknown
_1224829252.unknown
_1223990062.unknown
_1224063228.unknown
_1224063229.unknown
_1224063155.unknown
_1223990645.unknown
_1223990750.unknown
_1223990261.unknown
_1223584282.unknown
_1223990049.unknown
_1223986726.unknown
_1223584262.unknown
_1223494547.unknown
_1223496340.unknown
_1223496432.unknown
_1223498026.unknown
_1223496373.unknown
_1223495939.unknown
_1223495953.unknown
_1223494875.unknown
_1223495884.unknown
_1222794832.unknown
_1223385298.unknown
_1223494452.unknown
_1223494520.unknown
_1223385524.unknown
_1223494434.unknown
_1223385691.unknown
_1223385321.unknown
_1222795314.unknown
_1223385062.unknown
_1223385174.unknown
_1223385216.unknown
_1223385070.unknown
_1223384386.unknown
_1223384463.unknown
_1223143562.unknown
_1222795092.unknown
_1222794380.unknown
_1222794766.unknown
_1222794082.unknown
_1222794379.unknown