Question

17)

In a survey, 26 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $32 and standard deviation of $14. Construct a confidence interval at a 90% confidence level. Give your answers to one decimal place. Enter the confidence interval in the form: Sample Mean ± Margin of Error

You intend to estimate a population mean μμ with the following sample.

13	17	13	14
11	16	18	17
15	18	14	17

You believe the population is normally distributed. Find the 99% confidence interval for the population mean. Enter your answer as an open-interval (i.e., parentheses) accurate to two decimal places.

99% C.I. =

Karen wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 20 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 7.4 and a standard deviation of 3.3.

Find a 80% confidence interval for the number of chocolate chips per cookie for Big Chip cookies?

Round your answers to one decimal place.

Answer 1