Smart book | Chapter 6

Choose the random variables from this set that are discrete. Select all that apply. a. The number of concert tickets sold. b. The number of persons riding on a bus. c. The height of a person from a class of eight. d. The life span of a parakeet.

a,b

A random variable can be defined as:

a quantity resulting from a random experiment that can have different values

A grocer selects five apples randomly from a box, weighs them and calculates an average weight of 165 grams. Match the feature of this process to the correct term. Experiment Outcome Event Random Variable

- Selecting and weghing the apples -165 grams average weight -an average weight between 150 and 165 grams - The average weight of five apples

A software salesman knows that on average he will make one sale for every ten companies he calls. Let "success" be making a sale. (P(success)=0.10) Use binomial probability formula to find the chance that he will make two sales if he calls 6 companies.

0.098 Reason: x=2, n=6, π=0.1; P(2)=6C2(0.1)^2(0.9)^4

Place the following computational steps in the order in which you would do them to find the standard deviation for a probability distribution. Start with the one you would do first at the top.

1. Calculate the mean of the distribution 2. subtract the mean from each value and square the difference 3. multiply each squared difference by its probability 4. sum the products to find the variance 5. take the square root of the variance

Which of the following formulas is used to calculate the mean of a probability distribution?

Look up

A quantity representing the outcome of a random experiment that can assume different values is called a:

Random Variable

From the following list, choose the random variables that are continuous. Select all that apply. a. The average annual return on a certain bond. b. The tire pressure in a randomly selected automobile. c. The number of clubs in a poker hand. d. The number of students attending a lecture.

a,b

A Binomial experiment has independent trials and the outcome of a trial can be classified as either a success or a failure. Which two of the following statements also describe features of a binomial experiment? a. The random variable counts the number of successes in a fixed number of trials. b. After the first trial, subsequent trials are conditional probabilities. c. The probability of success stays the same for each trial. d. The distribution is always asymmetric in shape.

a,c

Jerry rolls a pair of dice and counts a total of seven dots on the uppermost faces of the dice. Match the feature of this process to the correct term. a. Experiment b. Outcome c. Event d. Random Event

a. rolling the dice and counting dots b. getting a 4 on one die and a 3 on the other c. getting dice that total 7 d. the number of dots showing

What is a Discrete Random Variable? a. A random variable that can only take on integer values. b. A random variable that can assume only separate distinct values. c. A variable that can take on any value within a specified range. d. A random variable that can take on only one particular value at a time.

b. A random variable that can assume only separate distinct values.

Choose the statements that describe characteristics of a Probability Distribution. Select all that apply. a. The distribution is symmetrical. b. The probability of an outcome is between 0 and 1 inclusive. c. The outcomes are mutually exclusive events. d. The sum of the probabilities of all possible outcome is one. e. Half of the possible outcomes have associated probabilities greater than 0.5

b. The probability of an outcome is between 0 and 1 inclusive. c. The outcomes are mutually exclusive events. d. The sum of the probabilities of all possible outcome is one.

Which of the following statements best describes a Probability Distribution? a. A listing of the least likely and most likely outcomes of a random experiment. b. A diagram that has branches extending from a root and sets of branches represent stages. c. A list of the outcomes of a random experiment and the probability of each outcome.

c. A list of the outcomes of a random experiment and the probability of each outcome.

What shows the possible outcomes of a random experiment and the probability of each outcome? a. A Scatter Diagram b. A Stem and Leaf Plot c. A Random Number Table d. A Probability Distribution

d.