Question

g People between the ages of 65 and 70 were studied to see if those who exercise more were healthier. One measure of health was blood pressure. The number of people at each level of blood pressure and amount of exercise are: Amount of Exercise Blood Pressure None Moderate High High 54 23 7 Normal 86 76 32 a. If the person selected had high blood pressure, what is the probability he or she did not exercise

Answer 1

If the person selected had high blood pressure, the probability that he or she did not exercise is P=0.643.

Explanation:

We have a group of people between agss of 65 and 70.

They are divided in two groups regarding their amount of exercise: "none", "moderate" and "high".

The response variable is blood pressure, that was categorized as "normal"or "high".

Then, we have the frequencies table as:

Amount of exercise None Moderate High

Blood pressure High 54 23 7

Blood pressure Normal 86 76 32

We have to calculate the probability that, given that the person had high blood pressure, he or she did not exercise.

If the person had high blood pressure, it can be of the any of the 3 groups of exercise amount. There are 54 people with high blood pressure that did not exercise, 23 that did moderate amount of exercise, and 7 that did a high amount.

Then, the probability can be calculated dividing the amount of people that had high blood pressure and did not exercise, by all the people that have high blood pressure (regarding the amount of exercise):

`P(N | HP)=(54)/(54+23+7)=(54)/(84)=0.643`

If the person selected had high blood pressure, the probability that he or she did not exercise is P=0.643.