AP Stats Exam Review

Question 1

when do you use binomial distribution?

Answer 1

1. fixed number of trials (n)
2. 2 outcomes, success and failure
3. probability of success the same for each trial
   Want to know “what is the probability of X successes in n trials”

Question 2

Binomial Distribution–20 trials, probability of success = 0.35, what is the probability of 5 successes?

Answer 2

Calculator:

binomialpdf(20, .35. 5)

Question 3

Binomial Distribution–20 trials, probability of success = 0.35, what is the probability of 5 successes or less?

Answer 3

Calculator:

binomialcdf(20, .35, 5)

Question 4

What is stratified sampling?

Answer 4

Divide the whole group into subgroups, such as high school into freshman, sophomores, juniors seniors, or a whole group into males and females, randomly sample from each group