Random samples of size 64 are drawn from the population in Example 2. Find the mean and standard deviation of the sampling distribution of sample means. Then sketch a graph of the sampling distribution and compare it with the sampling distribution in Example 2.

a. Find μ_x̅ and σ_x̅.

b. If n ≥ 30, sketch a normal curve with mean μ_x̅ and standard deviation σ_x̅.

c. Compare the results with those in Example 2.

Example 2

Cell phone bills for residents of a city have a mean of $47 and a standard deviation of $9, as shown in the figure. Random samples of 100 cell phone bills are drawn from this population, and the mean of each sample is determined. Find the mean and standard deviation of the sampling distribution of sample means. Then sketch a graph of the sampling distribution.

Distribution for All Cell Phone Bills

Transcribed Image Text:

29 38 47 56 65 Individual cell phone bills (in dollars)