Question

The average American young adult spends $140 on smartphone expenses per month, with a known population standard deviation of 28.2. In order to compute a confidence interval estimate for the population mean, a sample of 66 observations is drawn. Use Table 1.

a.	Is the condition that X−X−  is normally distributed satisfied?
	Yes No

b.	Compute the margin of error at a 95% confidence level. (Round intermediate calculations to 4 decimal places. Round final answer to 2 decimal places.)

Margin of error

  

c.

Compute the margin of error at a 95% confidence level based on a larger sample of 265 observations. (Round intermediate calculations to 4 decimal places. Round final answer to 2 decimal places.) **The next question will ask you to provide the two confidence interval values for this question, so write down your answers and data-enter your answers in the next question that appears on this test (after you answer "d." below).

Margin of error

  

d.	Which of the two margins of error will lead to a wider confidence interval?

Answer 1