In: Math
According to a study, the proportion of people who are satisfied with the way things are going in their lives is 0.76. Suppose that a random sample of 100 people is obtained. Complete parts (a) through (e) below.
(a) Suppose the random sample of100 people is asked, "Are you satisfied with the way things are going in your life?" Is the response to this question qualitative orquantitative? Explain.
A.The response is quantitative because the responses can be measured numerically and the values added or subtracted, providing meaningful results.
B.The response is quantitative because the responses can be classified based on the characteristic of being satisfied or not.
C.The response is qualitative because the responses can be measured numerically and the values added or subtracted, providing meaningful results.
D.The response is qualitative because the responses can be classified based on the characteristic of being satisfied or not.
(b) Explain why the sample proportion, ModifyingAbove p with caretp, is a random variable. What is the source of the variability?
A. The sample proportion ModifyingAbove p with caretp is a random variable because the value of ModifyingAbove p with caretp represents a random person included in the sample. The variability is due to the fact that different people feel differently regarding their satisfaction.
B. The sample proportion ModifyingAbove p with caretp is a random variable because the value of ModifyingAbove p with caretp represents a random person included in the sample. The variability is due to the fact that people may not be responding to the question truthfully.
C. The sample proportion ModifyingAbove p with caretp is a random variable because the value of ModifyingAbove p with caretp varies from sample to sample. The variability is due to the fact that people may not be responding to the question truthfully.
D. The sample proportion ModifyingAbove p with caretp is a random variable because the value of ModifyingAbove p with caretp varies from sample to sample. The variability is due to the fact that different people feel differently regarding their satisfaction.
(c) Describe the sampling distribution of ModifyingAbove p with caretp, the proportion of people who are satisfied with the way things are going in their life. Be sure to verify the model requirements.
Since the sample size is no
more
less
than 5% of the population size and np(1minus−p)equals=nothinggreater than or equals≥10, the distribution of ModifyingAbove p with caretp is
▼
skewed left
approximately normal
skewed right
uniform
with mu Subscript ModifyingAbove p with caret Baseline equalsμp=(BLANK)
and
sigma Subscript ModifyingAbove p with caret Baseline equalsσp=(BLANK).
(Round to three decimal places as needed.)
(d) In the sample obtained in part (a), what is the probability that the proportion who are satisfied with the way things are going in their life exceeds
0.7878?
The probability that proportion who are satisfied with the way things are going in their life exceeds 0.7878 is BLANK
(Round to four decimal places as needed.)
(e) Using the distribution from part (c), would it be unusual for a survey of 100 people to reveal that 70 or fewer people in the sample are satisfied with their lives?The probability that
70 or fewer people in the sample are satisfied is BLANK, which
▼
is not
is
unusual because this probability
▼
is
is not
less than
▼
5
0.05
0.5
50
%.
(Round to four decimal places as needed.)
a)
option D.The response is qualitative because the responses can be classified based on the characteristic of being satisfied or not.
b)
option D. The sample proportion ModifyingAbove p with caretp is a random variable because the value of ModifyingAbove p with caretp varies from sample to sample. The variability is due to the fact that different people feel differently regarding their satisfaction.
c)
Since the sample size is no more than 5% of
the population size and
np(1−p)equals=(100*0.76*0.24=)18.24 greater than
or equals≥10, the distribution of p hat is approximately
normal with
=0.76 and
=(
(0.76*0.24/100)
= 0.043
d)
The probability that proportion who are satisfied with the way things are going in their life exceeds 0.78
P(X>0.78) =
Z=(0.78-0.76)/0.043 = 0.4651
P(X>0.78) =P(Z≥0.4651)= 1 - 0.6791 = 0.3209
e)here p cap=70/100 =0.70
The probability that 70 or fewer people in the sample are satisfied is 0.0815, which
is not unusual because this probability is not less than 5%