Name:_____________________________________________________________________Date:___________Score:______/30 Unit 7 Assessment Version A Answer all questions thoroughly. A response without appropriate work will not receive credit. Be sure to show what you are plugging into all formulas and calculator functions used.

1. The Red Cross anticipates the need for at least 1850 units of O-negative blood. It estimates it will collect blood from 32,000 donors. Only 6% of the population has O-negative blood. What is the probability that the Red Cross will receive at least 1850 units of O-negative blood? (4 points)

2. When Joe bowls, he can get a strike (knocking down all the pins) 60% of the time. How many times more likely is it for Joe to bowl at least 3 strikes out of four tries as it is for him to bowl zero strikes in 4 tries? Round your answer to the nearest whole number. (5 points)

3. Ms. Downing is really excited to plan a ski vacation in February. The probability that it snows on any given day in February is 45%. (8 pts total)

a. If she’s planning to go away for 5 days, how many snowy days can she expect?

b. On what day should she first expect snow?

c. What is the probability that it snows on at least 3 days of her trip?

d. What is the probability that it does not snow at all on her trip?

4. A fifty question multiple-choice test consists of questions which each have four possible choices for the answers to each question.

a. What model (geometric, binomial, or normal) is most appropriate for this question? Explain your choice. (3 pts)

b. Estimate the probability of answering at least 70% of the questions correctly if all the answers are random guesses(3 pts)

5. Shortly after the introduction of the euro coin in Belgium, newspapers around the world published articles claiming that the coin was biased. The stories were based on reports that someone had spun the coin 250 times and had gotten 140 heads—that’s 56% heads. Do you think this is evidence that spinning the euro is unfair? Explain, using mathematical reasoning to justify your answer. (7 pts)