EDU 7211: Correlation and Regression � Exercise 5

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					Correlation and regression                                                                1


EDU 7211: Correlation and Regression – Exercise 5

Twenty-five married women who had one or more children 18 years of age or younger
and were living with a spouse or partner were subjects in a study. All of the women were
employed by small banks (defined as having fewer than 100 employees), and all had
occupations related to customer service (e.g., loan officer, teller, and credit card
operators). Among other things, they responded to six items on lack of flexibility in their
work schedule (sample item: “I can arrive at work and leave whenever I choose”) and
five items on spillover from work to parenting (sample item: “When I get home from
work, I often do not have the energy to be a good parent”)

The scores of 10 of the sample women are presented in the table below. Higher scores on
Variable X indicate less flexibility in work schedule. Higher scores on Variable Y
indicate increased spillover from work to parenting.

Use this information and that which follows to complete this exercise.

Subject                       Lack of Flexibility (X)       Spillover from Work (Y)__
1                             16                            22
2                             22                            23
3                             16                            20
4                             14                            19
5                             18                            22
6                             10                            23
7                             12                            16
8                             19                            21
9                             17                            18
10                            10                            13______________________

Mean (X) = 15.40              Mean (Y) = 19.70
SD (X) = 3.92                 SD (Y) = 3.27
Cov xy = 7.02

   1.      Construct a scatterplot of these scores. Describe what you see in the
           scatterplot – what does it suggest about the relationship between X and Y?

   2.      Compute the Pearson correlation between X and Y.

   3.      What percentage of the variance in Spillover from Work to Parenting is
           accounted for by Lack of Flexibility?

   4.      Compute and write the regression equation for predicting Spillover from Lack
           of Flexibility.

   5.      What is the predicted Spillover score for a woman with a Lack of Flexibility
           score of 22?
Correlation and regression                                                           2



   6.      What is the prediction error for Subject #2?

   7.      Draw the regression line using X=5 and X = 25 as your extreme scores.

   This problem was adapted from an article by MacDermid, S.M., Williams, S. M.,
   Marks, S., & Heilbrum, G. (1994). Is small beautiful? Work family tension, work
   conditions, and organizational size. Family Relations, 43, 159-167.

				
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