General Instructions: You must show your work to get partial credit! In most cases this willinvolve showing the formula(s), your initial substitutions, and the answer. No work, nopartial credit. If you use Excel, that shows your work. For the hypothesis testing problems,you must show the 7-step procedure demonstrated in class. Round z values to 2decimal places and t values to 3 decimal places, except when directed otherwise.Round pvalues to 4 decimal places.

1.Suppose you want to estimate the average age of all Boeing 727 airplanes now in

active domestic service. You want to be 95% confident and you want your

estimate to be within 3 years of the actual figure. The 727 was first placed in serviceabout 35 years ago, so you know that no active 727s are more than 35 years old.

This makes your estimate for the standard deviation equal to 8.75 years.How large asample should you take? Show Your Work! Formula(s), Substitutions, Answers! Roundyour z or t value to 2 decimal places.