Statistics Chapter 5 Review

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 ½

• The chance that the 100th toss will be a head depends somewhat on the previous 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; 0-6 means “yes” and 7-9 means “no”

• One digit simulates the result; 0-9 tells how many in the sample said “yes”

• Two digits simulate one person’s answer; 00-61 mean “yes” and 62-99 mean “no”

• Two digits simulate one person’s answer; 00-62 mean “yes” and 63-99 mean “no”

Choose an American household at random and record the number of vehicles they own. Here is the probability model if we ignore the households that own more than 5 cars: 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%

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

• 0.227

• 0.255

• 0.450

• 0.475

• 0.506

Choose the statistical question:

• What time did you wake up this morning?

• What time do 12th graders wake up each morning during the school week?

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

• 0.727

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

• 0.365

• 0.727

If you flip a coin two times, is it independent or dependent probability?

• Independent

• Dependent

Is this probability assignment possible?

• YES! Because all probabilities add up to 1!

• NO! Because it doesn't have enough probabilities.

• NO! Because the probabilities do not add up to 1.

• NO! Because one cannot speak 1, 2, 3, 4, or 5 languages.

What is the chance that the dessert is not brownies and does not have peanut butter in it?

• 0.58

• 0.42

• 0.06

• 0.05