Question

A smart phone manufacturer is interested in constructing a 90% confidence interval for the proportion of smart phones that break before the warranty expires. 89 of the 1692 randomly selected smart phones broke before the warranty expired. Round answers to 4 decimal places where possible.

a. With 90% confidence the proportion of all smart phones that break before the warranty expires is between _______ and _______ .

b. If many groups of 1692 randomly selected smart phones are selected, then a different confidence interval would be produced for each group. About ____ percent of these confidence intervals will contain the true population proportion of all smart phones that break before the warranty expires and about _____ percent will not contain the true population proportion.

Answer 1