Identifying Binomial Experiments

Decide whether the experiment is a binomial experiment. If it is not, explain why. Surveying 250 prisoners to see how many crimes in which they were convicted. The random variable represents the number of crimes in which each prisoner was convicted.

• Yes, since there are only two possible outcomes.

• No, since there are more than two possible outcomes.

Decide whether the experiment is a binomial experiment. If it is not, explain why. Surveying 600 prisoners to see whether they are serving time for their first offense. The random variable represents the number of prisoners serving time for their first offense.

• Yes, since there are only two possible outcomes.

• No, since there are way too many possible outcomes.

Decide whether the experiment is a binomial experiment. If it is not, explain why. You test four pain relievers. The random variable represents the pain reliever that is most effective.

• Yes, since there are only two possible outcomes.

• No, since there are too many possible outcomes.

Find the mean of the binomial distribution for which n =40 and p =0.2.

• 8

• 2.53

• 20

• 40

Find the variance of the binomial distribution for which

n =800 and p =0.87.

• 9.51

• 90.48

• 696

• 32.54

A test consists of 800 true or false questions. If the student guesses on each question, what is the standard deviation of the number of correct answers?

• 20

• 2

• 0

• 14.14

In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizens are chosen, what is the standard deviation of the number favoring the substation?

• 1.55

• 2.40

• 0.98

• 0.55

The probability that an individual is left-handed is 0.16. In a class of 10 students, what is the mean and standard deviation of the number of left-handers in the class?

• mean: 1.6; standard deviation: 1.26

• mean: 10; standard deviation: 1.16

• mean: 1.6; standard deviation: 1.16

• mean: 10; standard deviation: 1.26

Twenty-six percent of people in the United States with Internet access go online to get news. A random sample of five Americans with Internet access is selected and asked if they get the news online. Identify the values of n, p, and q, and list the possible values of the random variable x.

• n = 5; p = 0.74; q = 0.26; x = 0, 1, 2, 3, 4, 5

• n = 5; p = 0.26; q = 0.84; x = 0, 1, 2, 3, 4, 5

• n = 5; p = 0.26; q = 0.26; x = 1, 2, 3, 4, 5

• n = 6; p = 0.84; q = 0.26; x = 1, 2, 3, 4, 5

Fifty-seven percent of families say that their children have an influence on their vacation plans. Consider a sample of eight families who are asked if their children influence their vacation plans. Find the probability of exactly 5 families who said yes that their children have an influence on their vacation plans.

• 0.126

• 0.268

• 0.765

• 0.011