MHR 668 | Course Paper

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The Dean of Students conducted a survey on campus. Class designation (Freshman,

Sophomore, Junior, Senior) is an example of a ________ variable.

Suppose Z has a standard normal distribution with a mean of 0 and standard deviation

of 1. So, 85% of the possible Z values are smaller than ________.

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, what is the p-value of the test statistic when testing

whether being married or not makes a difference in the mean number of weeks a worker

is unemployed due to a layoff while holding constant the effect of all the other

independent variables?

Referring to Table 14-15, what is the p-value of the test statistic when

testing whether mean teacher salary has any effect on percentage of

students passing the proficiency test, taking into account the effect of

instructional spending per pupil?

TABLE 14-15

The superintendent of a school district wanted to predict the

percentage of students passing a sixth-grade proficiency test. She

obtained the data on percentage of students passing the proficiency

test (% Passing), mean teacher salary in thousands of dollars

(Salaries), and instructional spending per pupil in thousands of dollars

(Spending) of 47 schools in the state.

Following is the multiple regression output with Y = % Passing as the

dependent variable, X1 = Salaries and X2 = Spending:

TABLE 9-10

A manufacturer produces light bulbs that have a mean life of at least 500 hours when

the production process is working properly. Based on past experience, the population

standard deviation is 50 hours and the light bulb life is normally distributed. The

operations manager stops the production process if there is evidence that the population

mean light bulb life is below 500 hours.

Referring to Table 9-10, if you select a sample of 100 light bulbs and are willing to have

a level of significance of 0.10, the probability of a Type II error is ________ if the

population mean bulb life is 490 hours.

TABLE 8-10

A sales and marketing management magazine conducted a survey on salespeople

cheating on their expense reports and other unethical conduct. In the survey on 200

managers, 58% of the managers have caught salespeople cheating on an expense report,

50% have caught salespeople working a second job on company time, 22% have caught

salespeople listing a ‘strip bar” as a restaurant on an expense report, and 19% have

caught salespeople giving a kickback to a customer.

Referring to Table 8-10, the sampling error of a 95% confidence interval estimate of the

population proportion of managers who have caught salespeople cheating on an

expense report is ________.

TABLE 6-6

According to Investment Digest, the arithmetic mean of the annual return for common

stocks over an 85-year period was 9.5%, but the value of the variance was not

mentioned. Also 25% of the annual returns were below 8%, while 65% of the annual

returns were between 8% and 11.5%. The article claimed that the distribution of annual

return for common stocks was bell-shaped and approximately symmetric. Assume that

this distribution is normal with the mean given above. Answer the following questions

without the help of a calculator, statistical software or statistical table.

Referring to Table 6-6, what is the value above which will account for the highest 25%

of the possible annual returns?