Use the normal distribution to approximate the desired probability.
-Merta reports that 74% of its trains are on time. A check of 60 randomly selected trains shows that 38 of them arrived on time. Find the probability that among the 60 trains, 38 or fewer arrive on time. Based on the result, does it seem plausible that the "on-time" rate of 74% could be correct?
A) 0.0316, no
B) 0.0409, no
C) 0.0409, yes
D) 0.0316, yes

Question

Quizplus · Accepted Answer

The probability of 38 or fewer trains arriving on time is approximately 0.0409, which is quite low, suggesting that the "on-time" rate of 74% may not be correct.

Use the Normal Distribution to Approximate the Desired Probability