Question

A survey of 25 randomly selected customers found the ages shown (in years). The mean is 32.00 years and the standard deviation is 9.99 3 years. a Construct a 99% confidence interval for the mean age of all customers, assuming that the assumptions and conditions or the con interval have been met b) How large is the margin of error? c) How would the confidence interval change i you had assumed that the standard deviation was known to be 10.0 years? 25 a) What is the confidence interval? OD (Round to two decimal places as needed.) b) What is the margin of error? The margin of error is □ (Round to two decimal places as needed.) c) What is the confidence interval using the given population standard deviation? Select the correct choice below and filin the answer boxes within Round to two decimal places as needed.) 0 A. The new confidence interval ( , ) is narrower than O B. The new confidence interval ( ) is wider than the interval from part the interval from part a.

Answer 1