Question

The length of time needed to complete a certain test is normally distributed with mean 62 minutes and standard deviation 8 minutes. Find the probability that it will take less than 74 minutes to complete the test.a) 0.0668b) 0.5334c) 0.5000d) 0.4666e) 0.9332

Answer 1

Answer: the correct option is e

Step-by-step explanation:

Since the The length of time needed to complete a certain test is normally distributed, we would apply the the formula for normal distribution which is expressed as

z = (x - u)/s

Where

x = The length of time needed to complete a certain test

u = mean time

s = standard deviation

From the information given,

u = 62 minutes

s = 8 minutes

We want to find the probability the probability that it will take less than 74 minutes to complete the test. It is expressed as

P(x lesser than or equal to 74)

For x = 74,

z = (74 - 62)/8 = 1.5

Looking at the normal distribution table, the corresponding value for the z score is 0.9332

P(x lesser than or equal to 74) = 0.9332