Suppose the mean? per-person check for brunch at a restaurant chain is approximately ?$13

Suppose the mean? per-person check for brunch at a restaurant chain is approximately

?$13.50.

Complete parts? (a) through? (c) below.

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Part 1

a. Assuming a standard deviation of

?$5.00?,

what sample size is needed to? estimate, with

90?%

?confidence, the mean? per-person check for brunch to within

±?$0.75??

The sample size needed is

enter your response here.

?(Round up to the nearest? integer.)

b. Assuming a standard deviation of

?$6.50?,

what sample size is needed to? estimate, with

90?%

?confidence, the mean? per-person check for brunch to within

±?$0.75??

The sample size needed is

enter your response here.

?(Round up to the nearest? integer.)

c. Discuss the effect of variation on the sample size needed.

For the same level of confidence and sampling? error, how are variation and sample size needed? related?

A.

Populations with greater variability require smaller samples to accurately estimate the mean.

B.

Populations with greater variability require larger samples to accurately estimate the mean.

C.

There is no relation between variation and sample size needed.