In: Statistics and Probability
A random sample of 1008 adults in a certain large country was asked "Do you pretty much think televisions are a necessity or a luxury you could do without?" Of the 1008 adults surveyed, 511 indicated that televisions are a luxury they could do without. Complete parts (a) through (e) below.
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(a) Obtain a point estimate for the population proportion of adults in the country who believe that televisions are a luxury they could do without.
ModifyingAbove p with caretpequals=nothing
(Round to three decimal places as needed.)
(b) Verify that the requirements for constructing a confidence interval about p are satisfied.
The sample
▼
is stated to not be?
is stated to be ?
cannot be assumed to be ?
can be assumed to be ?
a simple random sample, the value of
▼
n ModifyingAbove p with caretnp
ModifyingAbove p with caret left parenthesis 1 minus ModifyingAbove p with caret right parenthesisp1−p
nn
ModifyingAbove p with caretp
n ModifyingAbove p with caret left parenthesis 1 minus ModifyingAbove p with caret right parenthesisnp1−p
is
nothing ,
which is
▼
less than
greater than or equal to
10, and the
▼
sample proportion ?
population proportion ?
population size ?
sample size ?
▼
is stated to not be?
can be assumed to be ?
is stated to be ?
cannot be assumed to be?
less than or equal to 5% of the
▼
sample proportion. ?
population size. ?
sample size. ?
population proportion. ?
(Round to three decimal places as needed.)
(c) Construct and interpret a
95%
confidence interval for the population proportion of adults in the country who believe that televisions are a luxury they could do without. Select the correct choice below and fill in any answer boxes within your choice.
(Type integers or decimals rounded to three decimal places as needed. Use ascending order.)
A.
We are
nothing %
confident the proportion of adults in the country who believe that televisions are a luxury they could do without is between
nothing ? answer..
and
nothing .? answer...
B.
There is a
answer? %
chance the proportion of adults in the country who believe that televisions are a luxury they could do without is between
answer?
and
answer?
(d) Is it possible that a supermajority (more than 60%) of adults in the country believe that television is a luxury they could do without? Is it likely?
It is
▼
likely ?
not possible ?
possible, but not likely ?
that a supermajority of adults in the country believe that television is a luxury they could do without because the
95%
confidence interval
▼
contains?
does not contain ?
nothing .
(Type an integer or a decimal. Do not round.)
(e) Use the results of part (c) to construct a
95%
confidence interval for the population proportion of adults in the country who believe that televisions are a necessity.
The
95%
confidence interval is
(nothing ,nothing ).
(Round to three decimal places as needed.)
More?
Less?
Solution:-
a) The point estimate for the population proportion of adults in the country who believe that televisions are a luxury they could do without is 0.5069.
x = 511, n = 1008
b)
The sample can be assumed to be simple random sample.
and are greater than 10.
Sample size can be assumed to be less than or equal to 5% of the population size.
c) (A) There is a 95 % chance the proportion of adults in the country who believe that televisions are a luxury they could do without is between 0.476 and 0.538.
95% confidence interval for the population proportion of adults in the country who believe that televisions are a luxury they could do without is C.I = ( 0.4760, 0.5378).
C.I = 0.5069 + 1.96 × 0.01575
C.I = 0.5069 + 0.030864
C.I = ( 0.4760, 0.5378)
d)
It is possible, but not likely that a super majority of adults in the country believe that television is a luxury they could do without because the 95% confidence interval does not contain the 0.60, all the values in the 95% confidence is less than 60%.
(e) The 95% confidence interval is C.I = ( 0.462, 0.524).
x = 497, n = 1008
C.I = 0.4931 + 1.96 × 0.015747
C.I = 0.4931 + 0.03086
C.I = ( 0.4622, 0.5240)
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