MGT 398 Quiz 2 | Course Paper

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True or False: TABLE 17-11

A logistic regression model was estimated in order to predict the probability that a

randomly chosen university or college would be a private university using information

on mean total Scholastic Aptitude Test score (SAT) at the university or college, the

room and board expense measured in thousands of dollars (Room/Brd), and whether the

TOEFL criterion is at least 550 (Toefl550 = 1 if yes, 0 otherwise.) The dependent

variable, Y, is school type (Type = 1 if private and 0 otherwise).

Referring to Table 17-11, there is not enough evidence to conclude that SAT score

makes a significant contribution to the model in the presence of the other independent

variables at a 0.05 level of significance.

True or False: TABLE 17-10

Given below are results from the regression analysis where the dependent variable is

the number of weeks a worker is unemployed due to a layoff (Unemploy) and the

independent variables are the age of the worker (Age), the number of years of education

received (Edu), the number of years at the previous job (Job Yr), a dummy variable for

marital status (Married: 1 = married, 0 = otherwise), a dummy variable for head of

household (Head: 1 = yes, 0 = no) and a dummy variable for management position

(Manager: 1 = yes, 0 = no). We shall call this Model 1. The coefficient of partial

determination ( ) of each of the 6 predictors are, respectively,

0.2807, 0.0386, 0.0317, 0.0141, 0.0958, and 0.1201.

Model 2 is the regression analysis where the dependent variable is Unemploy and the

independent variables are Age and Manager. The results of the regression analysis are

given below:

Referring to Table 17-10, Model 1, we can conclude that, holding constant the effect of

the other independent variables, the number of years of education received has no

impact on the mean number of weeks a worker is unemployed due to a layoff at a 10%

level of significance if all we have is the information on the 95% confidence interval

estimate forÎ²2.

TABLE 10-7

A buyer for a manufacturing plant suspects that his primary supplier of raw materials is

overcharging. In order to determine if his suspicion is correct, he contacts a second

supplier and asks for the prices on various identical materials. He wants to compare

these prices with those of his primary supplier. The data collected is presented in the

table below, with some summary statistics presented (all of these might not be

necessary to answer the questions which follow). The buyer believes that the

differences are normally distributed and will use this sample to perform an appropriate

test at a level of significance of 0.01.

True or False: Referring to Table 10-7, the null hypothesis should be rejected.

True or False: TABLE 17-10

Given below are results from the regression analysis where the dependent variable is

the number of weeks a worker is unemployed due to a layoff (Unemploy) and the

independent variables are the age of the worker (Age), the number of years of education

received (Edu), the number of years at the previous job (Job Yr), a dummy variable for

marital status (Married: 1 = married, 0 = otherwise), a dummy variable for head of

household (Head: 1 = yes, 0 = no) and a dummy variable for management position

(Manager: 1 = yes, 0 = no). We shall call this Model 1. The coefficient of partial

determination ( ) of each of the 6 predictors are, respectively,

0.2807, 0.0386, 0.0317, 0.0141, 0.0958, and 0.1201.

Model 2 is the regression analysis where the dependent variable is Unemploy and the

independent variables are Age and Manager. The results of the regression analysis are

given below:

Referring to Table 17-10 and using both Model 1 and Model 2, there is insufficient

evidence to conclude that the independent variables that are not significant individually

are significant as a group in explaining the variation in the dependent variable at a 5%

level of significance.

TABLE 16-13

Given below is the monthly time-series data for U.S. retail sales of building materials

over a specific year.

The results of the linear trend, quadratic trend, exponential trend, first-order

autoregressive, second-order autoregressive and third-order autoregressive model are

presented below in which the coded month for the 1st month is 0:

Linear trend model:

Quadratic trend model:

Exponential trend model:

First-order autoregressive:

Second-order autoregressive:

Third-order autoregressive:

Below is the residual plot of the various models:

True or False: Referring to Table 16-13, you can conclude that the third-order

autoregressive model is appropriate at the 5% level of significance.

True or False: If you randomly select a student from the first row of a business statistics

class and then every other fifth student thereafter until you get a sample of 20 students,

this is an example of a convenience sample.

TABLE 12-20

A filling machine at a local soft drinks company is calibrated to fill the cans at a mean

amount of 12 fluid ounces and a standard deviation of 0.5 ounces. The company wants

to test whether the standard deviation of the amount filled by the machine is 0.5 ounces.

A random sample of 15 cans filled by the machine reveals a standard deviation of 0.67

ounces.

True or False: Referring to Table 12-20, the decision is to reject the null hypothesis

when using a 10% level of significance.

True or False: The confidence interval obtained will always correctly estimate the

population parameter.

True or False: To determine the probability of getting more than 3 events of interest in a

binomial distribution, you will find the area under the normal curve for X = 3.5 and

above.

TABLE 14-17

Given below are results from the regression analysis where the

dependent variable is the number of weeks a worker is unemployed

due to a layo! (Unemploy) and the independent variables are the age

of the worker (Age) and a dummy variable for management position

(Manager: 1 = yes, 0 = no).

The results of the regression analysis are given below:

True or False: Referring to Table 14-17, we can conclude de.nitively

that, holding constant the e!ect of the other independent variable,

age has an impact on the mean number of weeks a worker is

unemployed due to a layo! at a 10% level of signi.cance if all we

have is the information of the 95% con.dence interval estimate for

the e!ect of a one year increase in age on the mean number of

weeks a worker is unemployed due to a layo!.

True or False: An interaction term in a multiple regression model may be used when the

relationship between X1 and Y changes for differing values of X2.

True or False: The C in the DCOVA framework stands for “categorize.”

TABLE 8-7

A hotel chain wants to estimate the mean number of rooms rented daily in a given

month. The population of rooms rented daily is assumed to be normally distributed for

each month with a standard deviation of 240 rooms. During February, a sample of 25

days has a sample mean of 370 rooms.

True or False: Referring to Table 8-7, a 90% confidence interval calculated from the

same data would be narrower than a 99% confidence interval.

True or False: If the sample sizes in each group is larger than 5, the Kruskal-Wallis rank

test statistic can be approximated by a chi-square distribution.

Four surgical procedures currently are used to install pacemakers. If the patient does not

need to return for follow-up surgery, the operation is called a “clear” operation. A heart

center wants to compare the 4 procedures, and collects the following numbers of

patients from their own records:

Which of the following tests will be the most appropriate to find out which of the 4

procedures is the most effective?

A) Ï‡2 test for difference in proportions

B) Z test for difference in proportions

C) One-way ANOVA F test for differences among more than two means

D) The Marascuilo procedure

TABLE 16-3

The following table contains the number of complaints received in a department store

for the first 6 months of last year.

Referring to Table 16-3, if this series is smoothed using exponential smoothing with a

smoothing constant of , what would be the second value?

A) 39

B) 42

C) 45

D) 53

TABLE 13-12

The manager of the purchasing department of a large saving and loan organization

would like to develop a model to predict the amount of time (measured in hours) it

takes to record a loan application. Data are collected from a sample of 30 days, and the

number of applications recorded and completion time in hours is recorded. Below is the

regression output:

Referring to Table 13-12, the value of the measured t-test statistic to test whether the

amount of time depends linearly on the number of loan applications recorded is

A) 0.8924.

B) 3.2559.

C) 15.2388.

D) 232.2200.

Referring to Table 14-4, what fraction of the variability in house size is explained by

income and size of family?

TABLE 14-4

A real estate builder wishes to determine how house size (House) is influenced by

family income (Income) and family size (Size). House size is measured in hundreds of

square feet and income is measured in thousands of dollars. The builder randomly

selected 50 families and ran the multiple regression. Partial Microsoft Excel output is

provided below:

Also SSR (X1âˆ£ X2) = 36400.6326 and SSR (X2âˆ£ X1) = 3297.7917

A) 17.56%

B) 70.69%

C) 71.89%

D) 84.79%

TABLE 2-16

The figure below is the percentage polygon for the amount of calories for a sample of

36 pizza products where the upper limits of the intervals are: 310, 340, 370, 400 and

430.

Referring to Table 2-16, roughly what percentage of pizza products contains at least 340

calories?

A) 25%

B) 28%

C) 39%

D) 61%

TABLE 2-5

The following are the duration in minutes of a sample of long-distance phone calls

made within the continental United States reported by one long-distance carrier.

Referring to Table 2-5, if 100 calls were sampled, ________ of them would have lasted

less than 5 minutes or at least 30 minutes or more.

A) 35

B) 37

C) 39

D) None of the above.

TABLE 17-1

A real estate builder wishes to determine how house size (House) is influenced by

family income (Income), family size (Size), and education of the head of household

(School). House size is measured in hundreds of square feet, income is measured in

thousands of dollars, and education is in years. The builder randomly selected 50

families and ran the multiple regression. Microsoft Excel output is provided below:

Referring to Table 17-1, at the 0.01 level of significance, what conclusion should the

builder draw regarding the inclusion of School in the regression model?

A) School is significant in explaining house size and should be included in the model

because its p-value is less than 0.01.

B) School is significant in explaining house size and should be included in the model

because its p-value is more than 0.01.

C) School is not significant in explaining house size and should not be included in the

model because its p-value is less than 0.01.

D) School is not significant in explaining house size and should not be included in the

model because its p-value is more than 0.01.

A major department store chain is interested in estimating the mean amount its credit

card customers spent on their first visit to the chain’s new store in the mall. Fifteen

credit card accounts were randomly sampled and analyzed with the following results:

= $50.50 and S = 20. Assuming the distribution of the amount spent on their first visit is

normal, what is the shape of the sampling distribution of the sample mean that will be

used to create the desired confidence interval for ?

A) approximately normal with a mean of $50.50

B) a standard normal distribution

C) a t distribution with 15 degrees of freedom

D) a t distribution with 14 degrees of freedom

Suppose that past history shows that 60% of college students prefer Brand C cola. A

sample of 5 students is to be selected. The probability that 2 or fewer prefer brand C is

________.

Which of the following types of samples can you use if you want to make valid

statistical inferences from a sample to a population?

A) a judgment sample

B) a quota sample

C) a convenience sample

D) a probability sample

TABLE 1-2

A Wall Street Journal poll asked 2,150 adults in the United States a series of questions

to find out their view on the U.S. economy.

Referring to Table 1-2, the possible responses to the question “How satisfied are you

with the U.S. economy today with 1 = very satisfied, 2 = moderately satisfied, 3 =

neutral, 4 = moderately dissatisfied, and 5 = very dissatisfied?” result in

A) a nominal scale variable.

B) an ordinal scale variable.

C) an interval scale variable.

D) a ratio scale variable.

TABLE 11-1

An airline wants to select a computer software package for its reservation system. Four

software packages (1, 2, 3, and 4) are commercially available. The airline will choose

the package that bumps as few passengers as possible during a month. An experiment is

set up in which each package is used to make reservations for 5 randomly selected

weeks. (A total of 20 weeks was included in the experiment.) The number of passengers

bumped each week is obtained, which gives rise to the following Excel output:

ANOVA

Referring to Table 11-1, the within groups degrees of freedom is

A) 3.

B) 4.

C) 16.

D) 19.

True or False: The geometric mean is a measure of variation or dispersion in a set of

data.

TABLE 19-1

The following payoff table shows profits associated with a set of 3 alternatives under 2

possible states of nature

Referring to Table 19-1, if the probability of S1 is 0.2 and S2 is 0.8, then the expected

opportunity loss (EOL) for A1 is

A) 0.

B) 1.2.

C) 4.8.

D) 5.6.

Referring to Table 14-17, what is the p-value of the test statistic to

determine whether there is a signi.cant relationship between the

number of weeks a worker is unemployed due to a layo! and the

entire set of explanatory variables?

TABLE 14-17

Given below are results from the regression analysis where the

dependent variable is the number of weeks a worker is unemployed

due to a layo! (Unemploy) and the independent variables are the age

of the worker (Age) and a dummy variable for management position

(Manager: 1 = yes, 0 = no).

The results of the regression analysis are given below:

The probability that a standard normal variable Z is positive is ________.

TABLE 13-4

The managers of a brokerage firm are interested in finding out if the number of new

clients a broker brings into the firm affects the sales generated by the broker. They

sample 12 brokers and determine the number of new clients they have enrolled in the

last year and their sales amounts in thousands of dollars. These data are presented in the

table that follows.

Referring to Table 13-4, the managers of the brokerage firm wanted to test the

hypothesis that the population slope was equal to 0. For a test with a level of

significance of 0.01, the null hypothesis should be rejected if the value of the test

statistic is ________.

TABLE 13-4

The managers of a brokerage firm are interested in finding out if the number of new

clients a broker brings into the firm affects the sales generated by the broker. They

sample 12 brokers and determine the number of new clients they have enrolled in the

last year and their sales amounts in thousands of dollars. These data are presented in the

table that follows.

Referring to Table 13-4, the least squares estimate of the Y-intercept is ________.

TABLE 4-9

A survey conducted by the Segal Company of New York found that in a sample of 189

large companies, 40 offered stock options to their board members as part of their

noncash compensation packages. For small- to mid-sized companies, 43 of the 180

surveyed indicated that they offer stock options as part of their noncash compensation

packages to their board members.

Referring to Table 4-9, if a company is selected at random, what is the probability that

the company is small to mid-sized or offered stock options to their board members?