1. A quantity resulting from an experiment by chance that can assume different values is called A. Ran dom sample B. Random variable C. Random process D. Random experiment 2. Which of the following is NOT a true statement? A. Random variables can only have one value. B. The value of a random variable could be zero. C. The probability of all the value of a random variable could be zero. D. The sum of all the probabilities in a probability distribution is always equal to one. 3. If a coin is tossed, what are the possible values of the random variable for t number of heads? A. O, 1 В. о, 1, 2 С. 1, 2, 3 D. 0, 1, 2, 3

A variable y of a finite population has the frequency distribution shown in the table. Suppose a member is selected at random from the population and let Y denote the value of the variable y for the member obtained. Complete parts (a) through (d) below. y 3 4 6. f 1 1 11 7 a. Determine the probability distribution of the random variable Y. 3 y P(Y = y) (Type integers or decimals. Do not round.) b. Use random-variable notation to describe the events that Y takes on the value 5, a value less than 5, and a value of at least 5. The event that Y takes on the value 5 can be represented as The event that Y takes on a value less than 5 can be represented as The event that Y takes on a value of at least 5 can be represented as { }. c. Find P(Y = 5), P(Y 5). %3D P(Y = 5) = (Type an integer or a decimal. Do not round.) P(Y<5) = (Type an integer or a decimal. Do not round.) P(Y 2 5) = (Type an integer or a decimal. Do not round.) LO

2. The probability model of the number of dinners that a typical American cook in a week is as follows. Number of dinners: 1 3 4 6. 7. Probability: 0.05 0.05 0.1 0.15 0.15 0.2 ? 0.2 Complete the probability table (find the missing probability)

What requirement must be met to be a true random sample? A.The probability of selecting one individual is independent of selecting another individual. B. The probability of being selected stays constant from one selection to another. C. Each individual has an equal chance of being selected for the sample. D. All of the answers are correct. E. Sampling is done with replacement.

12. A survey conducted discovered that 63% of all Americans are overweight. Suppose that a number of randomly selected Americans are weighed. The following table may (or may not) be useful: k 0 1 2 3 4 1 4 6 4 1 4Ck (a) Find the probability that the 4th person weighed is the first person to be overweight. (b) Find the probability that it takes less than 4 people to observe the first overweight person. (c) Find the expected value and variance of the number of Americans that would have to be weighed in order to find the first person that was overweight.

4. Final: In a monthly report, the local animal shelter states that it curently has 21 dogs and 27 cats. Fourteen of the dogs and 18 of the cats are female. If an animal is selected at random, find the probability that the pet is a male dog. O a. 4283 O b.1458 O c.5194 O d. .2319 Previous page Jump to. 近