Question

A map and GPS application for a smartphone was tested for accuracy. The

experiment yielded 26 error out of the 74 trials. Find the 95% confidence interval

estimate for the proportion of errors

Answer 1

$\hat p=\frac{26}{74}=0.3514.$

$95\%CI=(0.3514-1.96\sqrt{\frac{0.3514(1-0.3514)}{74}},0.3514+1.96\sqrt{\frac{0.3514(1-0.3514)}{74}})=$

$=(0.2426,0.4601).$