Question

1.Assume that a sample is used to estimate a population mean μμ. Find the 99% confidence interval for a sample of size 490 with a mean of 36.5 and a standard deviation of 6.4. Enter your answer as a tri-linear inequality accurate to 3 decimal places.

2.Karen wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 41 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 14.1 and a standard deviation of 2.2. What is the 80% confidence interval for the number of chocolate chips per cookie for Big Chip cookies? Enter your answers accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).

3.Assume that a sample is used to estimate a population mean μμ. Find the 90% confidence interval for a sample of size 39 with a mean of 72.4 and a standard deviation of 10.1. Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places.

90% C.I. =

Answer 1