Question 16 4.3 pts

A statement that is the sum of the

products of the values of a random variable with its
probability is

the expected value.

the variation of the random

variable.

an experiment.

a probability distribution.

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Question 17 4.3 pts

In order to measure the dispersion

of a random variable, look at its

standard deviation.

mean

expected value.

average.

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Question 18 4.3 pts

The uniform distribution defined

over the interval from 20 to 40 has the probability density
function

f(x) = 1/40 for all x

f(x) = 1/2 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

f(x) = 1/20 for 0 ≤ x ≤ 20 and

f(x) = 1/40 for 21 ≤ x ≤ 40

f(x) = 1/20 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

Question

19 4.3 pts

If x is normally distributed with

mean 12 and standard deviation 2, then P(x ≤ 15) is

P(z ≤ 5/4).

P(z ≤ -3/2)

P(z ≤ 3/2)

P(z ≤ -5/4)

Question

20 12.9 ptsSkip to question text.

The high school GPAs of applicants

for admission to a college program are recorded and relative
frequencies are

calculated for the categories.

GPA

f(x)

x < 2.0 .12 2.0 ≤ x < 2.5 .35 2.5 ≤ x < 3.0 .30 3.0 ≤ x < 3.5 .10 3.5 ≤ x Complete the table to make this a valid probability distribution. What is the probability an applicant's GPA will be below 3.0? What is the probability an applicant's GPA will be 2.5 or above? Question 21 17.35 ptsSkip to question text. An instructor allows students to take an exam as many times as needed until the student obtains a passing grade. The following is a record of the number of students in a class of 20 who took the test and the number of tests taken in order to obtain a passing grade. Students Number of Tests 9 1 6 2 3 3 2 4 Use the relative frequency approach to construct a probability distribution and show that it satisfies the required condition. Find the expected value of the number of tests taken. Compute the variance. Compute the standard deviation. Question 22 17.35 ptsSkip to question text. A video rental store has two video cameras available for customers to rent. Historically, demand for cameras has followed this distribution. The revenue per rental is $40. If a customer wants a camera and none is available, the store gives a $15 coupon for tape rental. Demand Relative Frequency Revenue Cost 0 .20 0 0 1 .10 40 0 2 .05 80 0 3 .35 80 15 4 .30 80 30 What is the expected demand? What is the expected revenue? What is the expected cost? What is the expected profit? Question 23 17.35 ptsSkip to question text. The weight of a .5 cubic yard bag of landscape mulch is uniformly distributed over the interval from 38.5 to 41.5 pounds. Give a mathematical expression for the probability density function. What is the probability that a bag will weigh more than 40 pounds? What is the probability that a bag will weigh less than 39 pounds? What is the probability that a bag will weigh between 39 and 40 pounds? Question 24 4.3 pts Time series methods do not include smoothing trend projections trend projection adjusted for seasonlity regression analysis all of these are trend series methods Flag this Question Question 25 4.3 pts A regular pattern recurring over one-year (or shorter) periods is called seasonality cyclical component regression trend Question 26 4.3 pts To select a value for α for exponential smoothing use a large α when the series varies substantially. use a small α when the series has little random variability. use any value All of the alternatives are true. none of the alternatives are true Question 27 4.3 pts Causal models should avoid the use of regression analysis. attempt to explain a time series' behavior. do not use time series data. All of the alternatives are true. Question 28 4.3 pts The number of cans of soft drinks sold in a machine each week is recorded below. Develop forecasts using a three period moving average. 328, 191, 187, 156, 241, 232, 198, 195, 178, 220 Question 29 4.3 ptsSkip to question text. The number of girls who attend a summer basketball camp has been recorded for the seven years the camp has been offered. Use exponential smoothing with a smoothing constant of .8 to forecast attendance for the eighth year. 57, 78, 75, 102, 108, 131, 164 Question 30 4.3 pts A trend line for the attendance at a restaurant's Sunday brunch is given by Number = 246 + .27(t) How many guests would you expect in week 30?

Question 16 4.3 pts

A statement that is the sum of the

products of the values of a random variable with its
probability is

the expected value.

the variation of the random

variable.

an experiment.

a probability distribution.

Flag this Question

Question 17 4.3 pts

In order to measure the dispersion

of a random variable, look at its

standard deviation.

mean

expected value.

average.

Flag this Question

Question 18 4.3 pts

The uniform distribution defined

over the interval from 20 to 40 has the probability density
function

f(x) = 1/40 for all x

f(x) = 1/2 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

f(x) = 1/20 for 0 ≤ x ≤ 20 and

f(x) = 1/40 for 21 ≤ x ≤ 40

f(x) = 1/20 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

Question

19 4.3 pts

If x is normally distributed with

mean 12 and standard deviation 2, then P(x ≤ 15) is

P(z ≤ 5/4).

P(z ≤ -3/2)

P(z ≤ 3/2)

P(z ≤ -5/4)

Question

20 12.9 ptsSkip to question text.

The high school GPAs of applicants

for admission to a college program are recorded and relative
frequencies are

calculated for the categories.

GPA

f(x)

x < 2.0 .12 2.0 ≤ x < 2.5 .35 2.5 ≤ x < 3.0 .30 3.0 ≤ x < 3.5 .10 3.5 ≤ x Complete the table to make this a valid probability distribution. What is the probability an applicant's GPA will be below 3.0? What is the probability an applicant's GPA will be 2.5 or above? Question 21 17.35 ptsSkip to question text. An instructor allows students to take an exam as many times as needed until the student obtains a passing grade. The following is a record of the number of students in a class of 20 who took the test and the number of tests taken in order to obtain a passing grade. Students Number of Tests 9 1 6 2 3 3 2 4 Use the relative frequency approach to construct a probability distribution and show that it satisfies the required condition. Find the expected value of the number of tests taken. Compute the variance. Compute the standard deviation. Question 22 17.35 ptsSkip to question text. A video rental store has two video cameras available for customers to rent. Historically, demand for cameras has followed this distribution. The revenue per rental is $40. If a customer wants a camera and none is available, the store gives a $15 coupon for tape rental. Demand Relative Frequency Revenue Cost 0 .20 0 0 1 .10 40 0 2 .05 80 0 3 .35 80 15 4 .30 80 30 What is the expected demand? What is the expected revenue? What is the expected cost? What is the expected profit? Question 23 17.35 ptsSkip to question text. The weight of a .5 cubic yard bag of landscape mulch is uniformly distributed over the interval from 38.5 to 41.5 pounds. Give a mathematical expression for the probability density function. What is the probability that a bag will weigh more than 40 pounds? What is the probability that a bag will weigh less than 39 pounds? What is the probability that a bag will weigh between 39 and 40 pounds? Question 24 4.3 pts Time series methods do not include smoothing trend projections trend projection adjusted for seasonlity regression analysis all of these are trend series methods Flag this Question Question 25 4.3 pts A regular pattern recurring over one-year (or shorter) periods is called seasonality cyclical component regression trend Question 26 4.3 pts To select a value for α for exponential smoothing use a large α when the series varies substantially. use a small α when the series has little random variability. use any value All of the alternatives are true. none of the alternatives are true Question 27 4.3 pts Causal models should avoid the use of regression analysis. attempt to explain a time series' behavior. do not use time series data. All of the alternatives are true. Question 28 4.3 pts The number of cans of soft drinks sold in a machine each week is recorded below. Develop forecasts using a three period moving average. 328, 191, 187, 156, 241, 232, 198, 195, 178, 220 Question 29 4.3 ptsSkip to question text. The number of girls who attend a summer basketball camp has been recorded for the seven years the camp has been offered. Use exponential smoothing with a smoothing constant of .8 to forecast attendance for the eighth year. 57, 78, 75, 102, 108, 131, 164 Question 30 4.3 pts A trend line for the attendance at a restaurant's Sunday brunch is given by Number = 246 + .27(t) How many guests would you expect in week 30?

Question 16 4.3 pts

A statement that is the sum of the

products of the values of a random variable with its
probability is

the expected value.

the variation of the random

variable.

an experiment.

a probability distribution.

Flag this Question

Question 17 4.3 pts

In order to measure the dispersion

of a random variable, look at its

standard deviation.

mean

expected value.

average.

Flag this Question

Question 18 4.3 pts

The uniform distribution defined

over the interval from 20 to 40 has the probability density
function

f(x) = 1/40 for all x

f(x) = 1/2 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

f(x) = 1/20 for 0 ≤ x ≤ 20 and

f(x) = 1/40 for 21 ≤ x ≤ 40

f(x) = 1/20 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

Question

19 4.3 pts

If x is normally distributed with

mean 12 and standard deviation 2, then P(x ≤ 15) is

P(z ≤ 5/4).

P(z ≤ -3/2)

P(z ≤ 3/2)

P(z ≤ -5/4)

Question

20 12.9 ptsSkip to question text.

The high school GPAs of applicants

for admission to a college program are recorded and relative
frequencies are

calculated for the categories.

GPA

f(x)

x < 2.0 .12 2.0 ≤ x < 2.5 .35 2.5 ≤ x < 3.0 .30 3.0 ≤ x < 3.5 .10 3.5 ≤ x Complete the table to make this a valid probability distribution. What is the probability an applicant's GPA will be below 3.0? What is the probability an applicant's GPA will be 2.5 or above? Question 21 17.35 ptsSkip to question text. An instructor allows students to take an exam as many times as needed until the student obtains a passing grade. The following is a record of the number of students in a class of 20 who took the test and the number of tests taken in order to obtain a passing grade. Students Number of Tests 9 1 6 2 3 3 2 4 Use the relative frequency approach to construct a probability distribution and show that it satisfies the required condition. Find the expected value of the number of tests taken. Compute the variance. Compute the standard deviation. Question 22 17.35 ptsSkip to question text. A video rental store has two video cameras available for customers to rent. Historically, demand for cameras has followed this distribution. The revenue per rental is $40. If a customer wants a camera and none is available, the store gives a $15 coupon for tape rental. Demand Relative Frequency Revenue Cost 0 .20 0 0 1 .10 40 0 2 .05 80 0 3 .35 80 15 4 .30 80 30 What is the expected demand? What is the expected revenue? What is the expected cost? What is the expected profit? Question 23 17.35 ptsSkip to question text. The weight of a .5 cubic yard bag of landscape mulch is uniformly distributed over the interval from 38.5 to 41.5 pounds. Give a mathematical expression for the probability density function. What is the probability that a bag will weigh more than 40 pounds? What is the probability that a bag will weigh less than 39 pounds? What is the probability that a bag will weigh between 39 and 40 pounds? Question 24 4.3 pts Time series methods do not include smoothing trend projections trend projection adjusted for seasonlity regression analysis all of these are trend series methods Flag this Question Question 25 4.3 pts A regular pattern recurring over one-year (or shorter) periods is called seasonality cyclical component regression trend Question 26 4.3 pts To select a value for α for exponential smoothing use a large α when the series varies substantially. use a small α when the series has little random variability. use any value All of the alternatives are true. none of the alternatives are true Question 27 4.3 pts Causal models should avoid the use of regression analysis. attempt to explain a time series' behavior. do not use time series data. All of the alternatives are true. Question 28 4.3 pts The number of cans of soft drinks sold in a machine each week is recorded below. Develop forecasts using a three period moving average. 328, 191, 187, 156, 241, 232, 198, 195, 178, 220 Question 29 4.3 ptsSkip to question text. The number of girls who attend a summer basketball camp has been recorded for the seven years the camp has been offered. Use exponential smoothing with a smoothing constant of .8 to forecast attendance for the eighth year. 57, 78, 75, 102, 108, 131, 164 Question 30 4.3 pts A trend line for the attendance at a restaurant's Sunday brunch is given by Number = 246 + .27(t) How many guests would you expect in week 30?

A statement that is the sum of the

products of the values of a random variable with its
probability is

the expected value.

the variation of the random

variable.

an experiment.

a probability distribution.

Question 17 4.3 pts

In order to measure the dispersion

of a random variable, look at its

standard deviation.

mean

expected value.

average.

Question 18 4.3 pts

The uniform distribution defined

over the interval from 20 to 40 has the probability density
function

f(x) = 1/40 for all x

f(x) = 1/2 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

f(x) = 1/20 for 0 ≤ x ≤ 20 and

f(x) = 1/40 for 21 ≤ x ≤ 40

f(x) = 1/20 for 20 ≤ x ≤ 40 and

f(x) = 0 elsewhere

19 4.3 pts

If x is normally distributed with

mean 12 and standard deviation 2, then P(x ≤ 15) is

P(z ≤ 5/4).

P(z ≤ -3/2)

P(z ≤ 3/2)

P(z ≤ -5/4)

20 12.9 ptsSkip to question text.

The high school GPAs of applicants

for admission to a college program are recorded and relative
frequencies are

calculated for the categories.

GPA

f(x)