3 pts You have been given the task of estimating the proport

(3 pts) You have been given the task of estimating the proportion of Southwest flights that arrive “on time”, (which is no later than 15 minutes after the scheduled arrival time).How many flights must you survey in order to be 80% confident that your estimate is within .04 of the true population proportion?Assume that for a recent year, 84% of Southwest flights were on time (based on data from the Bureau of Transportation Statistics).Show work, answer question, and give units

Solution

Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.2 is = 1.28
Samle Proportion = 0.84
ME = 0.04
n = ( 1.28 / 0.04 )^2 * 0.84*0.16
= 137.6256 ~ 138