Homework 7
Could you please revise #’s 6, 9(a), 10(a), 18?
X6.
PriviteraStats2 15.E.021.
A therapist specializing in family counseling measures the relationship between partners and marital satisfaction. Husbands and wives rated how satisfied they were in their marriage using a 7-point rating scale ranging from 1 (not satisfied at all) to 7 (very satisfied). Using the hypothetical data given in the following table, compute the Pearson correlation coefficient. (Round your answer to three decimal places.)
|
Husband |
Wife |
|
X |
Y |
|
1 |
3 |
|
2 |
3 |
|
3 |
3 |
|
4 |
3 |
|
5 |
3 |
|
6 |
3 |
|
7 |
3 |
Since x increase y cannot increase hence correlation between x and y is undefended
PriviteraStats2 15.E.027.
Employers often use standardized measures to gauge how likely it is that a new employee with little to no experience will succeed in their company. One such factor is intelligence, measured using the Intelligence Quotient (IQ). To show that this factor is related to job success, an organizational psychologist measures the IQ score and job performance (in units sold per day) in a sample of 10 new employees.
|
IQ |
Job Performance |
|
100 |
17 |
|
115 |
38 |
|
108 |
30 |
|
98 |
15 |
|
120 |
42 |
|
147 |
56 |
|
132 |
48 |
|
85 |
53 |
|
105 |
21 |
|
110 |
36 |
X(a) Convert the following data to ranks and then compute a Spearman correlation coefficient. (Round your answer to three decimal places.) (b) Using a two-tailed test at a 0.05 level of significance, state the decision to retain or reject the null hypothesis.
Retain the null hypothesis. Reject the null hypothesis.
PriviteraStats2 15.E.029.
To test whether extracurricular activity is a good predictor of college success, a college administrator records whether students participated in extracurricular activities during high school and their subsequent college freshman GPA.
|
Extracurricular Activity |
College Freshman GPA |
|
Yes |
3.49 |
|
Yes |
3.37 |
|
Yes |
3.92 |
|
Yes |
3.74 |
|
No |
2.98 |
|
No |
3.81 |
|
No |
3.45 |
|
No |
2.75 |
|
No |
3.87 |
|
No |
2.85 |
X(a) Code the dichotomous variable and then compute a point-biserial correlation coefficient. (Round your answer to three decimal places.) (b) Using a two-tailed test at a 0.05 level of significance, state the decision to retain or reject the null hypothesis. Hint: You must first convert r to a t-statistic.
Retain the null hypothesis. Reject the null hypothesis.
PriviteraStats2 16.E.021.
An instructor measured quiz scores and the number of hours studying among a sample of 20 college students. If
SSXY = 48,
SSX = 98,
MY = 7,
and
MX = 5,
then what is the regression equation for this sample? (Round your numerical values to three decimal places.)
The regression equation is:
Y=0.5*x+4.5 = X + X
0.169
0.5
4.5
NAN
0.939