# 1) A sales presentative for a tire manufacturer claims that her steel-belted radials will last least 40,000 miles. A tire dealer decides to check this claim by testing 20 randomly chosen tires.

1) A sales presentative for a tire manufacturer claims that her steel-belted radials will last least 40,000 miles. A tire dealer decides to check this claim by testing 20 randomly chosen tires. If 75% or more of the 20 tires tested last at least 40,000 miles, the dealer will purchase tires from the sales representative. a. In extensive tests, the tire manufacturer establishes that 90% of the manufactured

tires last at least 40,000 miles. Is this a binomial situation? Explain.

b. Under the condition of part a (above), what is the probability that the tire dealer will

purchase tires from the sales representative?

2) A company that bakes chocolate chip cookies averages 5 chocolate chips per cookie.

Assume that the number of chocolate chip per cookie follows the Poisson distribution. a. What is the probability that a randomly selected cookie will contain 6 chocolate

chips? b. What is the probability that a randomly selected cookie will contain at most 6

chocolate chips? c. What is the likelihood that a randomly selected cookie will contain at least 5

chocolate chips? d. What is the probability that a randomly selected cookie will contain between 5 and 7

chocolate chips? 3) A 30 years old male in good health wishes to purchase a \$150,000 life insurance policy

payable at the time of his death. He needs the protection until he is 35 years old. The probability of dying on a given year between the ages 30 and 34 is given in the following table.

Age 30 31 32 33 34 Probability 0.0001 0.0001 0.0002 0.0002 0.0002

If the person pays a one-time \$500 premium for the policy, what is the expected profit or loss to the insurance firm if the person dies before age 35? 4) In a five-number summary, which of the following is NOT used for data summarization? a. the smallest number b. the largest number c. the median d. the mean

5) The symbol σis used to represent the

a. Population variance b. population standard deviation c. sample variance

6) The probability of at least one head in two flips of a coin is

a. 33% chance b. 50% chance c. 75% chance d. 90% chance

7. The sample space refers to

a. The sample size b. the set off all possible experimental outcomes

c. experimental outcomes are correct d. I don’t know.

8. Peter wants to find the probability of 7 customers arrivals in an hour at a bookstore, he

needs to use generally the a. The binomial probability distribution b. Poisson probability distribution

9. Variance is

a. a measure of the average, or central value of a random variable b. a measure of the dispersion of a random variable c. the square root of the standard deviation

10. A measure of the average value of a random variable is called a(n)

a. Variance b. standard deviation c. the expected value d. the mode