CON7300: Statistical Project Assignment (Part I), Semester 1, 2023
Instruction:
(A) Questions in this paper should be answered by students whose surnames fall within the range
G-M.
(B) Use the Excel files ‘Dataset5 and Dataset6’ to answer questions asked in Part A and
‘Dataset7’and ‘Dataset8’ to answer questions asked in Part B.
(C) A heavy penalty will be applied if your answers are not based on datasets assigned to you.
ECON7300: Statistical Project Assignment (Part I), Semester 1, 2023
Part A: Note: for questions in Part A assume that the three assumptions underlying
ANOVA (i.e., randomness and independence, normality, and homogeneity of
variance) are met. Use the closest degrees of freedom for the denominator to get
critical value from F-table.
(1) Using Dataset5 test at a 5% level of significance if there is any evidence of a significant
difference in the average time (time) in months elapsed before receiving a promotion for
employees in three groups defined by firm size (fsize). Follow all the necessary steps to
perform the test and verify your results using Excel/PHStat. Note: in your data, the variable
“fsize” is coded 1 for employees working in small firms, 2 for employees working in
medium-sized firms and 3 for employees working in large firms.
(2) If your results in (1) indicate that it is appropriate, use the Tukey-Kramer procedure to
determine which groups of fsize differ in average time elapsed before receiving a
promotion. Use a 5% level of significance. Follow all the necessary steps to perform the
test and verify your results using Excel/PHStat.
(3) Using Dataset6 test at a 5% level of significance if there is any evidence of a significant
difference in the average weekly wages (wage) for employees in three groups defined by
their work experience (exp). Follow all the necessary steps to perform the test and verify
your results using Excel/PHStat. Note: in your data, the variable “exp” is coded 1 for
employees with less than 10 years of work experience, 2 for employees with 10-15 years
of work experience and 3 for employees with more than 15 years of work experience.
(4) If your results in (3) indicate that it is appropriate, use the Tukey-Kramer procedure to
determine which groups of exp differ in average weekly wages. Use a 5% level of
significance. Follow all the necessary steps to perform the test and verify your results using
Excel/PHStat.
ECON7300: Statistical Project Assignment (Part I), Semester 1, 2023
Part B Note: for questions in Part B assume that the three assumptions underlying
ANOVA (i.e., randomness and independence, normality, and homogeneity of
variance) are met. Use the closest degrees of freedom for the denominator to get
critical value from F-table.
1. Plant therapists believe that plants can reduce on-the-job stress. A university study was
conducted to investigate this phenomenon. Two weeks prior to final exams, 8
undergraduate students took part in an experiment to determine what effect the presence of
a live plant, a photo of a plant or absence of a plant has on a student’s ability to relax while
isolated in a dimly lit room. Each student participated in three sessions – one with a live
plant (coded 1), one with a plant photo (coded 2) and one with no plant (coded 3). During
each session, finger temperature (temp) was measured at 1-minmute interval for 16
minutes. Because increasing finger temperature indicates an increased level of relaxation,
the maximum temperature (in Fahrenheit) was used as the response variable. The data for
the experiment is saved in ‘Dataset7’. Hint: the variable student is the blocking variable.
Based on the information given, answer the following questions.
(a) At the 5% level of significance, was blocking effective? Follow all the necessary steps and
verify your results using Excel/PHStat.
(b) Using a 5% level of significance, is there a significance difference in the mean finger
temperature (temp) of the three treatments (plant)? Follow all the necessary steps to
perform the test.
(c) If your results in (b) indicate that it is appropriate, use the Tukey procedure to determine
which groups of plant differ in the mean finger temperature. Use a 5% level of
significance. Follow all the necessary procedure to perform the test.
2. Suppose the Environmental Protection Agency (EPA) would like to investigate the impact
that octane has on six cars that were driven 1,000 miles with three different grades of
gasoline (gas): 87, 89 and 93 octanes. The gas mileage (gm) was recorded for each octane
level. Each car was tasted with all the three gasoline grades. These data are saved in
‘Dataset8’. Hint: the variable car is the blocking variable.
Based on the information given, answer the following questions.
(a) At the 1% level of significance, was blocking effective? Follow all the necessary steps and
verify your results using Excel/PHStat.
(b) Using a 1% level of significance, is there a significance difference in the mean gas mileage
(gm) of the three grades of gasoline (gas)? Follow all the necessary steps to perform the
test.
(c) If your results in (b) indicate that it is appropriate, use the Tukey procedure to determine
which groups of gas differ in the mean gas mileage (gm). Use a 1% level of significance.
Follow all the necessary procedure to perform the test.