Question 4:

Assume breast cancer affects 0.001 of the female population between 45 and 55 years of age.

There are two kinds of positive test results:

• True positive (the test indicates you have a disease, and you actually have it)
• False positive (the test indicates you have a disease, but you actually do not).

Assume mammograms are

• 0.92 accurate detecting people who actually have breast cancer (true positive rate)
• 0.90 accurate for people who do not have breast cancer (true negative rate).

Compute the probability that a female between the ages of 45 and 55 who tests positive for breast cancer has breast cancer, and enter your answer with 3 decimal places.