ejercicios de probabilidad(en)
TRANSCRIPT
8/11/2019 Ejercicios de Probabilidad(en)
http://slidepdf.com/reader/full/ejercicios-de-probabilidaden 1/3
l.
Exercises for
6.6
The mean rent for
a
one-bedroom apartment in Southern
California
is
$2,200
per
month.
The
distribution
of
the
monthly
costs does not follow the
normal distribution.
ln
fact,
it
is
positively
skewed.
What
is the
probability
of
selecting
a
sample
of
50 one-bedroom
apartments and
finding
the
mean
to
be
at least
$1,950
per
month? The
standard
deviation
of the sample is
$250.
According to
an
IRS
study,
it
takes an
average
of
330 minutes
for
taxpayers
to
prepare,
copy, and
electronically
file a
1040
tax
form.
A consumer watchdog
agency selects
a
random sample
of
40 taxpayers and
finds
the standard
deviation of
the
time
to
prepare,
copy, and
electronically
file
form 1040
is
80 minutes.
a. What assumption
or assumptions
do
you
need
to
make
about the
shape of
the
population?
b.
What
is the
likelihood
the
sample mean
is
greater
than
320 minutes?
c.
What
is
the
likelihood
the sample
mean
is
between 320
and
350 minutes?
d.
What is the
likelihood
the
sample
mean is
greater
than
350
minutes?
Recent studies indicate
that
the
typicat
5O-year-old woman spends
$350
per year
for
personal-care products.
The
distribution
of
the
amounts spent
is
positively
skewed. We
select
a
random
sample
of
40 women. The mean amount
spent
for
those sampled
is
$335,
and
the
standard
deviation of
the sample
is
$45.
What
is
the
likelihood of finding a
sample
mean
this
large or
larger from
the specified
population?
Information
from the American Institute of
Insurance
indicates the
mean amount
of
life
insurance
per
household
in
the
United
States
is
$110,000.
This
distribution
is
positively
skewed. The standard
deviation of
the
population
is
now known.A
random sample
of
50
households
revealed
a
mean
of
$
1
12,000 and
a standard
deviation of
$40,000.
a.
What
is
the likelihood
of
selecting
a sample
with
a
mean
of
at least
$112,000?
b.
What
is the
likelihood
of
selecting a sample
with
a
mean
of
more
than
$100,000?
c.
Find
the
likelihood of
selecting a sample
with
a
mean
of
more than
$100,000
but
less
than
$112000.
The mean age
at which
men in the
United States
marry for
the
first
time is
24.8
years.
The
shape
and
the
standard
deviation of
the
population
are both
unknown.
For
a
random
sample
of
60
men,
what
is
the
likelihood
that the
age
at
which
they
were married
for
the
first
time
is
less
than
25.1
years?
Assume
that the standard
deviation
of
the sample is 2.5
years.
A
recent study by the Greater Los Angeles
Taxi Drivers Association
showed
that the
mean fare charged
for
service
from
Hermosa
Beach to
the
Los Angeles
International
Airport
is
$18.00
and the standard
deviation is
$3.50.
We select
a
sample
of
15
fares.
What
is the
likelihood
that
the sample mean is
between
$17.00
and
$20.00?
)
J.
4.
5.
6.
8/11/2019 Ejercicios de Probabilidad(en)
http://slidepdf.com/reader/full/ejercicios-de-probabilidaden 2/3
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