Question

Probability:

A group of 80 people was surveyed to find out how many days a week they work out. The results are listed in the chart below. If a person is selected from the group at random, find the probability that they work out?

Answer 1

A: We want to select one person who works out three days a week. Our probability is simply 12/80 ~~ 15%

B: At least 4 days a week means 4 days, 5 days, or 6 days.
Hence, we have: (9 + 20 + 8)/80 = 46%

C: At least once a week.
Let's find out how many DO NOT work out and subtract that from our sample space. This means they must work out at least once a week.

(80 - 15)/80 = 81%