The following data set is from a study that looked at cell phone usage (minutes) according to age group.
This is your opportunity to put together much of what you have done thus far in the semester. You will also run an analysis on this data set and draw conclusions. If you can successfully complete this homework assignment, you will do well on the application portion of the mid-term exam.Please note: This lecture material (ANOVA) is covered on the midterm exam.
|
Age 19 yrs and under
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20-39
|
40-59
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60 and over
|
|
800
|
250
|
780
|
200
|
|
850
|
350
|
750
|
120
|
|
800
|
375
|
775
|
150
|
|
650
|
320
|
725
|
90
|
|
750
|
430
|
650
|
20
|
|
680
|
380
|
630
|
150
|
|
800
|
325
|
790
|
200
|
|
750
|
410
|
790
|
130
|
|
690
|
450
|
680
|
160
|
|
710
|
390
|
700
|
30
|
Complete the following:
1. Identify the Factor in this data set. ____________________________________________
2. How many levels of the factor are there?_______________________________________
3. What are the levels (name them)______________________________________________
4. Enter this data carefully into SPSS in the correct format for the chosen test from question 1
a. For directions about entering data, please go back to the SPSS directions or look at the corresponding lecture PDF. Please note: Points will be deducted if the data is entered into SPSS with errors. This will be apparent in the output.
b. Be sure to assign Value Labels for the grouping variable.
c. Label your variables with your last name included in the label. (See "Label" column, Slide 53)
5. Run all tests to assess Assumptions
6. Run the analysis:
a. Analyze>>compare Means>>One-Way ANOVA
b. Highlight and click the independent variable into the Factor box
c. Highlight and click the dependent variable into the Dependent List box
d. Click on Options
e. In the One-Way ANOVA: Options window check Descriptive, Homogeneity of Variance test and Means Plot.
f. Click on Continue
g. Click on Post-Hoc
h. Click on Scheffe, SNK, and Tukey
i. Click on Continue
j. Click on OK. The test will run and the output will generate.
7. The Output that you will obtain includes: (There are other tables and graphs that we will not address)
a. Descriptives (for Kurtosis and Skewness)
b. Q-Q Plot
c. Box Plot
d. Normality test table
e. Descriptives Table
f. Test of Homogeneity of Variances Table
g. ANOVA Table
h. Multiple Comparisons Table
i. Means Plot graph
8. Questions for Output: Please copy and paste the appropriate table or graph along in the same location as the question(s) being asked about that table or graph. Please scale the size down once they are pasted in the word document.
a. Interpret the Box Plot: (Paste Boxplot here)
i. Are there any outliers? YES NO
(If outliers do exist, proceed anyway)
b. Is the data normally distributed?(Paste appropriate Descriptive table, Normality test table, and QQ Plots here)
i. Calculate the Skewness for each level. Show the equation with the numbers that you used. Circle the answers that you calculated.
ii. Does there appear to be non-normally distributed groups? YES NO
iii. What groups APPEAR to be normally distributed?________________________
iv. Normality Test: What Test did you use? ________________________________
v. Were all of the groups normally distributed according to the test? YES NO
vi. Using the Q-Q plots, were all of the groups normally distributed? YES NO
vii. State your final decision on normality of the data. ______________________
c. Interpret the table forTest of Homogeneity of Variances. (Paste H of V table here)
i. What was the test statistic value? __________
ii. What was the p value? ___________
iii. Was the data homogenous in terms of variance? YES NO
d. Interpret the ANOVA Table. (Paste ANOVA table here)
i. The Between groups df was_______. How was this calculated?____________
ii. The Within groups df was_______. How was this calculated? ______________
iii. The Total df was_______. How was this calculated? _____________________
iv. What was the F-ratio obtained in this analysis? ________
1. Using information from the ANOVA table, how was this calculated?
(Write the equation with the correct numbers.)____________
v. Was the F-ratio significant? YES NO
1. What was the exact p-value? ___________
vi. Write the decision about the null hypothesis regarding this F-ratio_______________________________________________
e. Interpret the Multiple Comparisons Table.(Paste MC table here)
i. All three tests had similar results.
1. Which groups were found to be similar?____________________
2. Which groups were found to be different? __________________
ii. Which was the most conservative test? ____________________________
(Hint: Look at the calculated p-value for the groups showing no difference.)
9. Create the final write up. Be complete. Include the Means Plotgraph.
Please cut and paste the SPSS output tables and graphs into your homework at the designated location. PLEASE READ THIS ASSIGNMENT VERY CAREFULLY. ANSWER ALL QUESTIONS.