Q1.

Say, Apple Inc. claims that 21% of all Apple device users own an iPad. If a random sample of 314 Apple device users is selected, what is the Z score if 35% of those sampled own an iPad?Assume the conditions are satisfied.Give your answer correctly rounded to two decimal places.

Q2.

A salesperson created a 99% confidence interval of (279.91, 500.28) megabytes per month to estimate the average capacity usage of an iPhone.What is the value of the width of this confidence interval?Please give your answer correctly rounded to two decimal places and do NOT include units in your answer.

Q3.

An electricity provider wants to estimate the mean time it takes for customers to get an electrical fault resolved. The provider took a random sample of 36 customers who had recently reported an electrical fault and found a mean time of 13.41 hours.Assume the population standard deviation is 0.19 hours. What is the value of the margin of error for a 95% confidence interval?Please give your answer correctly rounded to two decimal places and do NOT give units.