Question

A survey on healthy choices was given to gym members at Work It Out. The results

showed that 90% of its members drank protein shakes. Of the members who drank

protein shakes, 30% took weight-loss medication whereas only 10% of members

who did not drink protein shakes took weight-loss medication. What is the

probability that a gym member does not take weight-loss medication?

1) 0.28

2) 0.66

3) 0.63

4) 0.72

Answer 1

The correct option is 4) 0.72.

Explanation:

Consider the provided information.

Let us consider that there are 100 members.

(Note: you can take any number the answer will remain the same.)

90% of its members drank protein shakes and of the members who drank protein shakes.

90% of 100 is 90.

Thus, 90 members drank protein shake.

Of the members who drank protein shakes, 30% took weight-loss medication.

30% of 90 is 27.

That means 27 out of 90 took weight loss medication.

Out of 100 members 90 drank protein shakes that means 10 members does not take protein shakes.

Only 10% of members who did not drink protein shakes took weight-loss medication.

10% of 10 is 1, that means 1 member out of 10 took weight loss medication.

Thus the required table is:

Medication Not Medication Total

Drank shakes 27 63 90

Doesn't Drank shakes 1 9 10

Total 28 72 100

Now we need to find the probability that a gym member does not take weight-loss medication.

72 out of 100 members does not take weight-loss medication.

Therefore, the required probability is:
`(72)/(100)=0.72`

Hence, the correct option is 4) 0.72.