A nutritionist wants to determine how much time nationally people spend eating a
ID: 3354072 • Letter: A
Question
A nutritionist wants to determine how much time nationally people spend eating and drinking. Suppose for a random sample of
10661066
people age 15 or older, the mean amount of time spent eating or drinking per day is
1.291.29
hours with a standard deviation of
0.640.64
hour. Complete parts (a) through (d) below.
(a) A histogram of time spent eating and drinking each day is skewed right. Use this result to explain why a large sample size is needed to construct a confidence interval for the mean time spent eating and drinking each day.
A.
The distribution of the sample mean will always be approximately normal.
B.
Since the distribution of time spent eating and drinking each day is not normally distributed (skewed right), the sample must be large so that the distribution of the sample mean will be approximately normal.
Your answer is correct.
C.
The distribution of the sample mean will never be approximately normal.
D.
Since the distribution of time spent eating and drinking each day is normally distributed, the sample must be large so that the distribution of the sample mean will be approximately normal.
(b) In 2010, there were over 200 million people nationally age 15 or older. Explain why this, along with the fact that the data were obtained using a random sample, satisfies the requirements for constructing a confidence interval.
A.
The sample size is less than 5% of the population.
Your answer is correct.
B.
The sample size is greater than 10% of the population.
C.
The sample size is greater than 5% of the population.
D.
The sample size is less than 10% of the population.
(c) Determine and interpret a
9999%
confidence interval for the mean amount of time Americans age 15 or older spend eating and drinking each day.
Select the correct choice below and fill in the answer boxes, if applicable, in your choice.
(Type integers or decimals rounded to three decimal places as needed. Use ascending order.)
A.
The nutritionist is
9999%
confident that the amount of time spent eating or drinking per day for any individual is between
nothing
and
nothing
hours.
B.
The nutritionist is
9999%
confident that the mean amount of time spent eating or drinking per day is between
nothing
and
nothing
hours.
C.
There is a
9999%
probability that the mean amount of time spent eating or drinking per day is between
nothing
and
nothing
hours.
D.
The requirements for constructing a confidence interval are not satisfied.
Explanation / Answer
The statistical software output for this problem is:
One sample T summary confidence interval:
: Mean of population
99% confidence interval results:
Hence,
Option B; The nutritionist is 99% confident that the mean amount of time spent eating or drinking per day is between 1.239 hours and 1.341 hours.
Mean Sample Mean Std. Err. DF L. Limit U. Limit 1.29 0.019602045 1065 1.2394178 1.3405822Related Questions
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