The ages of five randomly chosen cars in a parking garage are determined to be 7, 9, 3, 4, and 6 years old. If one considers this sample of 5 in groups of 3, what is the probability of the population mean falling between 5.5 and 6.5 years?

the answer is 4 out of 10 or 4/10 = 0.4

Step-by-step explanation:

from the question which says that the  ages of five randomly chosen cars in a parking garage are determined to be 7, 9, 3, 4, and 6 years old. If one considers this sample of 5 in groups of 3

solution

the number of groups of 3 that are possible implies that

5 choose 3 = 10 possible groups of 3

also,

the number of these groups of 3 that have a true mean of more than 6years needs to be considered.

The following groups add up to 19 or more ; (9,7,6), (9,7,4), ( 9,7,3) , (9,7,4).

therefore the answer is 4 out of 10 or 4/10 = 0.4