A random sample of 420 new Ford trucks showed that 105 requi

A random sample of 420 new Ford trucks showed that 105 required repairs within the first warranty estimate for the probability that a new Ford truck will not need repairs within the first warranty year? a. 0.25 b. 315 c. 0.75 d. 105

Solution

Sample proportion for no repairs = 420-105/420 = 0.75

Hence estimate = 0.75 i.e. option c