Intro Stats Probability

In the 2016 Summer Olympics, the United States and China won the most medals. Suppose we randomly select a medal from the 191 that are represented in the two-way table. Define events G: gold medal, U: United States, and B: bronze medal.

Find P(B | U)

• 0.199

• 0.314

• 0.594

• 0.770

Students who work at Swings Coffee shop recorded the drink orders of all the customers on a Saturday. They found that 64% of customers ordered a hot drink, and 80% of hot drink customers added cream to their drink. Find the probability that a randomly selected Saturday customer orders a hot drink and adds cream to the drink.

• 0.51

• 0.64

• 0.80

• 1.25

In 2015, Spotify revealed that about 47% of its users are aged 13–24, 25% are aged 25–34, and 28% are 35 or older. Suppose that for the 13- to 24-year-olds, 85% identified pop as their favorite music genre, 59% of the 25- to 34-year-olds identified pop as their favorite music genre, and 23% of the users 35 or older identified pop as their favorite music genre. Suppose we select one 2015 Spotify user at random and record their age and whether their favorite music genre is pop.

Find the probability that the person identifies their favorite music genre as pop.

• 1.67

• 0.12

• 0.61

• 0.40

In 2015, Spotify revealed that about 47% of its users are aged 13–24, 25% are aged 25–34, and 28% are 35 or older. Suppose that for the 13- to 24-year-olds, 85% identified pop as their favorite music genre, 59% of the 25- to 34-year-olds identified pop as their favorite music genre, and 23% of the users 35 or older identified pop as their favorite music genre. Suppose we select one 2015 Spotify user at random and record their age and whether their favorite music genre is pop. Suppose the chosen person identifies their favorite music genre as pop. What’s the probability that they are aged 13–24?

• 0.47

• 0.65

• 1.39

• 0.40

Ms. LaFever decides to give her AP Statistics class a pop quiz with 4 multiple-choice questions. Each multiple-choice question has 5 possible answer choices. David did not do the homework or do any studying, so he used the RandInt function on his calculator to guess on all 4 questions. What is the probability that David guesses correctly on all 4 questions?

• 0.0016

• 0.2000

• 0.8000

• none of the above

Which of the following is true for two events, each with probability greater than 0?

• If the events are mutually exclusive, they must be independent

• If the events are independent, they must be mutually exclusive

• If the events are not mutually exclusive, they must be independent

• If the events are not independent, they must be mutually exclusive

• If the events are mutually exclusive, they cannot be independent

Recent studies show that approx 65% of people are lactose intolerant. If a group of 10 people are randomly selected, what is the probability that exactly 8 of them are lactose intolerant?

• 0.0134

• 0.004

• 0.3500

• 0.6500

• 0.9140