# Question: A statistics student who worked as a cashier at the

A statistics student who worked as a cashier at the (former) electronics superstore Circuit City wanted to estimate the amount spent by customers using either credit or debit cards. She took a random sample of customers and recorded the amount they spent. Figure A shows a histogram of the data.

a. Figure B shows a 95% confidence interval for the mean amount spent. Interpret this confidence interval.

b. A log transform of the data shows a more normally distributed data set. Figure C shows a 95% confidence interval for the log (base 10) of the amounts spent. Convert the boundaries back into dollars by raising 10 to the power given as the boundary. Report and interpret the confidence interval for the geometric mean.

c. Which interval is narrower?

d. Which interval would you report if you wanted to tell a Circuit City manager about the typical amount of money spent via credit or debit cards? Explain.

a. Figure B shows a 95% confidence interval for the mean amount spent. Interpret this confidence interval.

b. A log transform of the data shows a more normally distributed data set. Figure C shows a 95% confidence interval for the log (base 10) of the amounts spent. Convert the boundaries back into dollars by raising 10 to the power given as the boundary. Report and interpret the confidence interval for the geometric mean.

c. Which interval is narrower?

d. Which interval would you report if you wanted to tell a Circuit City manager about the typical amount of money spent via credit or debit cards? Explain.

## Answer to relevant Questions

Morning Routine A statistics student conducted a survey to determine how much time students at her school spent getting ready to leave the house after they got up in the morning. Figure A shows a histogram of the times for ...Suppose you had to identify the color of ink for a series of printed words, but the printed word appeared in a color of ink that did not match the name of the color. For example, if you were shown "RED" then you should say ...A statistics student who was interested in credit card debt asked a random sample of students for the total amount of their credit card debt. We eliminated the two women and the one man who had a debt of 0, which left 18 ...Are women happier than men? A StatCrunch survey asked respondents to select a number from 1 (lowest) to 100 (highest) to measure their level of happiness. The sample mean for the 297 females was 71.15, and the sample mean ...Determine whether the population means number of texts sent and the population number received (for all the respondents) is different at the 0.05 level by using a paired t-test.Post your question