AP Statistics

How many people will I have to screen to find a Type O donor?  Use the ____ model.

• geometric
• binomial
• normal

An algebra 2 test has 6 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 6 questions, what is the probability that you get exactly 3 questions correct? (You need to figure out the p value first. It is not given to you.)

• 96.2%
• 13.2%
• 8.31%
• 25.0

Barry Bonds has a career batting average of .298.  What is the probability that he will get on base 6 times in 10 at bats?

• 3.58%
• 5.46%
• 22.67%
• 100%

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that at least 2 of the first 10 blood donors has Type B blood? 

• 0.088
• 0.697
• 0.214
• 0.303 

A Stats  test has 5 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 5 questions, what is the probability that you get exactly 2 questions correct?

• 0.6250
• 0.25
• 0.0625
• 0.2636

A company states that 2% of its computers are returned for defects.  We take a sample of 100 computers to find the probability of 10 being defective.  Is this a binomial distribution?

• No because there is not a fixed number of trials.
• No because their are more than 2 outcomes.
• Yes since there are a fixed number of independent trials, outcomes in 2 categories, and the probability of defect is constant.
• No since computers would not be independent.

You are a terrible driver. Whenever you drive, there is a 70% chance that you will run over a pedestrian. If you go for a drive 15 times, what is the probability that you will run over 7 or more pedestrians?

• 0.98
• 0.02
• 0.95
• 0.05

The probability that Jalen makes a free throw is 75%. What is the probability he makes his first free throw on his third attempt?

• geometcdf(3, 0.75)
• geometpdf(0.75, 3)
• geometpdf(3, 0.75)
• geometcdf(0.75, 3) 

The local Chipotle is running a promotion where each large drink cup has a large pull-off tab that reveals a prize (free burrito!) or the message "Try again next time."  Chipotle claims that 25% of the cups have tabs with a  prize.  You visit Chipotle to try to win.  What is the probability that you win on your third visit?

• 0.86
• 0.14
• 0.42
• 0.58

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. How many blood donors should the American Red Cross expect to collect from until it gets a donor with Type B blood? 

• 9.1 donors
• 8.5 donors
• 10.3 donors
• Cannot be determined.