The average age of a vehicle registered in the united states is 8 years, or 96 months. assume the standard deviation is 16 months. if a random sample of a group of 48 vehicles is selected find the probability that the mean of the groups age is between 90 and 100 months.

0.245

Step-by-step explanation:

In order to find find the probability that the mean of the groups age is between 90 and 100 months, we have to find z  for each value

Z = (x – mean)/standard deviation

Le x be the average age of a vehicle

Z1 = (90 – 96)/16 = -0.375

Z2 = (100 – 96)/16 =  0.25

Then we use the z table to find the area under the curve.

Area for Z1 = 0.354

Area for Z2 = 0.599

The probability that the mean of the groups age is between 90 and 100 months can be found as follows:

0.599 – 0.354 = 0.245

45

step-by-step explanation: