AP Stats - Chapter 5 Practice Test

Dr. Stats plans to toss a fair coin 10,000 times in the hope that it will lead him to a deeper understanding of the laws of probability. Which of the following statements is true?

• It is unlikely that Dr. Stats will get more than 5000 heads.

• Whenever Dr. Stats gets a string of 15 tails in a row, it becomes more likely that the next toss will be a head.

• The fraction of tosses resulting in heads should be exactly 1/2.

• The chance that the 100th toss will be a head depends somewhat on the results of the first 99 tosses.

• It is likely that Dr. Stats will get about 50% heads.

China has 1.2 billion people. Marketers want to know which international brands they have heard of. A large study showed that 62% of all Chinese adults have heard of Coca-Cola. You want to simulate choosing a Chinese at random and asking if he or she has heard of Coca-Cola. One correct way to assign random digits to simulate the answer is:

• One digit simulates one person’s answer; odd means “Yes” and even means “No.”

• One digit simulates one person’s answer; 0 to 6 mean “Yes” and 7 to 9 mean “No. ”

• One digit simulates the result; 0 to 9 tells how many in the sample said “Yes.”

• Two digits simulate one person’s answer; 00 to 61 mean “Yes” and 62 to 99 mean “No. ”

• Two digits simulate one person’s answer; 00 to 62 mean “Yes” and 63 to 99 mean “No. ”

Choose an American household at random and record the number of vehicles they own. If we ignore the few households that own more than 5 cars, the probability model is given in the picture.

A housing company builds houses with two-car garages. What percent of households have more cars than the garage can hold?

• 7%

• 13%

• 20%

• 45%

• 55%

Computer voice recognition software is getting better. Some companies claim that their software correctly recognizes 98% of all words spoken by a trained user. To simulate recognizing a single word when the probability of being correct is 0.98, let two digits simulate one word; 00 to 97 mean “correct.” The program recognizes words (or not) independently. To simulate the program’s performance on 10 words, use the random digits given in the picture.

The number of words recognized correctly out of the 10 is:

• 10

• 9

• 8

• 7

• 6

One thousand students at a city high school were classified according to both GPA and whether or not they consistently skipped classes. The two-way table given summarizes the data. Suppose that we choose a student from the school at random.

What is the probability that a student has a GPA under 2.0?

• 0.227

• 0.255

• 0.450

• 0.475

• 0.506

One thousand students at a city high school were classified according to both GPA and whether or not they consistently skipped classes. The two-way table given summarizes the data. Suppose that we choose a student from the school at random.

What is the probability that a student has a GPA under 2.0 or has skipped many classes?

• 0.080

• 0.281

• 0.285

• 0.365

• 0.506

One thousand students at a city high school were classified according to both GPA and whether or not they consistently skipped classes. The two-way table given summarizes the data. Suppose that we choose a student from the school at random.

What is the probability that a student has a GPA under 2.0 given that he or she has skipped many classes?

• 0.080

• 0.281

• 0.285

• 0.314

• 0.727

For events A and B related to the same chance process, which of the following statements is true?

• If A and B are mutually exclusive, then they must be independent.

• If A and B are independent, then they must be mutually exclusive.

• If A and B are not mutually exclusive, then they must be independent.

• If A and B are not independent, then they must be mutually exclusive.

• If A and B are independent, then they cannot be mutually exclusive.

Choose an American adult at random. The probability that you choose a woman is 0.52. The probability that the person you choose has never married is 0.25. The probability that you choose a woman who has never married is 0.11. The probability that the person you choose is either a woman or has never been married (or both) is therefore about

• 0.77

• 0.66

• 0.44

• 0.38

• 0.13

A deck of playing cards has 52 cards, of which 12 are face cards. If you shuffle the deck well and turn over the top 3 cards, one after the other, what’s the probability that all 3 are face cards?

• 0.001

• 0.005

• 0.010

• 0.012

• 0.02