Review CH 5 hw

The accompanying table describes the random variable​ x, the numbers of adults in groups of five who reported sleepwalking. Complete parts​ (a) through​ (d) below. a. Find the probability of getting exactly 4 sleepwalkers among 5 adults.

0.026

The accompanying table describes the random variable​ x, the numbers of adults in groups of five who reported sleepwalking. Complete parts​ (a) through​ (d) below. b. Find the probability of getting 4 or more sleepwalkers among 5 adults.

0.028

What is the mean of a probability​ distribution? Choose the correct answer below. A. The mean must be a possible value of the random variable. B. The mean represents the most likely outcome for the random variable. C. The mean gives information on how the outcomes vary. D. The mean is the expected value of the random variable.

D. The mean is the expected value of the random variable.

Explain how to find the mean of a discrete random variable. Choose the correct answer below. A. To find the mean of a random​ variable, multiply each value of the random variable by its probability and then add those products. B. To find the mean of a random​ variable, add the possible values of the random variable and divide by the number of possible values. C. To find the mean of a random​ variable, add the probabilities of each value and divide by the number of possible values. D. To find the mean of a random​ variable, find the weighted average of the squared​ deviations, using the probabilities as weights.

A. To find the mean of a random​ variable, multiply each value of the random variable by its probability and then add those products.

The accompanying table describes the random variable​ x, the numbers of adults in groups of five who reported sleepwalking. Complete parts​ (a) through​ (d) below. d. Is 4 a significantly high number of 4 sleepwalkers among 5​ adults? Why or why​ not? Use 0.05 as the threshold for a significant event. A. Yes, since the appropriate probability is less than​ 0.05, it is a significantly high number. B. Yes, since the appropriate probability is greater than​ 0.05, it is a significantly high number. C. No, since the appropriate probability is less than​ 0.05, it is not a significantly high number. D. No, since the appropriate probability is greater than​ 0.05, it is not a significantly high number.

A. Yes, since the appropriate probability is less than​ 0.05, it is a significantly high number.

Find the mean of the random variable x. Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice. A. μ = ____ adult(s) ​(Round to one decimal place as​ needed.) B. The table does not show a probability distribution.

A. μ = 1.6 adult(s) ​(Round to one decimal place as​ needed.)

Find the standard deviation of the random variable x. Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice. A. σ =______​adult(s) ​(Round to one decimal place as​ needed.) B. The table does not show a probability distribution.

A. σ =.9 ​adult(s) ​(Round to one decimal place as​ needed.)

A sociologist randomly selects single adults for different groups of​ three, and the random variable x is the number in the group who say that the most fun way to flirt is in person. Determine whether a probability distribution is given. If a probability distribution is​ given, find its mean and standard deviation. If a probability distribution is not​ given, identify the requirements that are not satisfied. Does the table show a probability​ distribution? Select all that apply. A.Yes, the table shows a probability distribution. B. No, the random variable​ x's number values are not associated with probabilities. C. No, the random variable x is categorical instead of numerical. D. No, not every probability is between 0 and 1 inclusive. E. No, the sum of all the probabilities is not equal to 1.

A.Yes, the table shows a probability distribution.

Determine whether the distribution is a discrete probability distribution. If​ not, state why. Choose the correct answer below. A. No, because the probabilities do not sum to 1. B. No, because some of the probabilities are negative and they must all be between 0 and 1 inclusive. C. No, because 0 is not an acceptable value for a discrete random variable. D. Yes, the distribution is a discrete probability distribution.

B. No, because some of the probabilities are negative and they must all be between 0 and 1 inclusive.

Identify the requirements for a discrete probability distribution. Choose the correct answer below. A. The sum of the probabilities must equal one. B. The sum of the probabilities must equal one. Each probability must be between zero and one inclusive. C. There must be a fixed number of independent trials. There must be two mutually exclusive outcomes for each trial with a constant probability of success. D. Each probability must be between zero and one inclusive.

B. The sum of the probabilities must equal one. Each probability must be between zero and one inclusive.

Determine whether the distribution is a discrete probability distribution. If​ not, state why. Choose the correct answer below. A. ​No, because the probabilities must all be between 0 and 1 inclusive.. B. ​Yes, the distribution is a discrete probability distribution. C. ​No, because the probabilities do not sum to 1. D. ​No, because 0 is not an acceptable value for a discrete random variable.

C. ​No, because the probabilities do not sum to 1.

The accompanying table describes the random variable​ x, the numbers of adults in groups of five who reported sleepwalking. Complete parts​ (a) through​ (d) below. c. Which probability is relevant for determining whether 4 is a significantly high number of sleepwalkers among 5​ adults: the result from part​ (a) or part​ (b)? A. Since the probability of getting 5 sleepwalkers is less likely than getting 4​ sleepwalkers, the result from part​ (a) is the relevant probability. B. Since the probability of getting 4 sleepwalkers is the result from part​ (a), this is the relevant probability. C. Since the probability of getting fewer than 4 sleepwalkers is the complement of the result from part​ (b), this is the relevant probability. D. Since the probability of getting 5 sleepwalkers includes getting 4​ sleepwalkers, the result from part​ (b) is the relevant probability.

D. Since the probability of getting 5 sleepwalkers includes getting 4​ sleepwalkers, the result from part​ (b) is the relevant probability.

In a probability​ histogram, there is a correspondence between ______?

area and probability

Determine whether the value is a discrete random​ variable, continuous random​ variable, or not a random variable. a. The distance a baseball travels in the air after being hit b. The amount of rain in City Upper B during April c. The response to the survey question "Did you smoke in the last week?" d. The number of textbook authors now sitting at a computer e. The number of points scored during a basketball game f. The number of bald eagles in a country

a. It is a continuous random variable. b. It is a continuous random variable. c. It is not a random variable. d. It is a discrete random variable. e. It is a discrete random variable. f. It is a discrete random variable.

A​ _______ random variable has infinitely many values associated with measurements.

continuous

A​ _______ random variable has either a finite or a countable number of values.

discrete