# Thread: Hi guys need help before my test

1. ## Hi guys need help before my test

I have part I but am unsure how to do part 2 and 3. Any help would be greatly appreciated

a) For women aged 40-65, the prevalence rate of breast cancer is 800 pet 100,000. A particular
diagnostic test is accurate for 85% of women with breast cancer and for 95% of women
who do not have breast cancer.
(i) The diagnostic test is positive for a particular woman. What is the probability that
she has breast cancer?(ii) Given a sample of n women, let X denote the number of women who have breats

cancer. State what the probability distribution of this random variable is, and justify
(iii) If 10,000 women were tested, how many would you expect to have breast cancer?

2. ## Re: Hi guys need help before my test

Hey MathJack.

Hint for 2: If each woman has the same chance of getting cancer and they are all independent, then the distribution will be a Binomial distribution. (Can you use your previous answer to get the parameter for the Binomial?)

3. ## Re: Hi guys need help before my test

For part 2 does it want me to use the .008 or the answer from part one? The wording seems like it wants meto use the .008, also There is no sample size so would I just use n as a parameter