A multiple linear regression was used to study how family spending (Y) is influenced by income (X1), family size (X2), and additions to savings (X3). The variables Y, X1, and X3are measured in thousands of dollars per year. The following results were obtained. ANOVA
DF SS
Regression 45.9634
Residual 11 2.6218
Total
Coefficients Standard Error
Intercept 0.0136
X1 0.7992 0.074
X2 0.2280 0.190
X3 -0.5796 0.920
1. What was the number of families used in this study?
a. 12
b. 13
c. 14
d. 15
2. The predicted annual spending of family of size 4 making $90,000 a year, and adding $5,000 annually to their savings is:.
a. $58,491
b. $62,385
c. $69,956
d. $75,603
3. If the family addition to savings increases by $1000, and the values of family income and size remain fixed, the predicted annual family spending:.
a. increase by $799.2
b. decreases by $799.2
c. increases by $579.6
d. decreases by $579.6
4. The percent of variations in family spending explained by family income, size and additions to savings is
a. 94.6
b. 90.7
c. 86.4
d. 83.6
5. The value of the Fstatistic for testing the overall significance of the regression model is:.
a. 10.75
b. 64.28
c. 50.19
d. 17.21
6. The p-value for testing the overall significance of the regression model is:.
a. less than 0.01
b. between 0.01 and 0.025
c. between 0.025 and 0.05
d. more than 0.05
7. At 5% significance level, the critical Fvalue for testing the overall significance of the model is:.
a. 3.71
b. 2.76
c. 3.59
d. 6.22
8. At 1% significance level, the conclusion is that the:.
a. model is insignificant
b. model is significant
c. x1 is insignificant
d. x3 is significant
9. The value of the tstatistic for testing whether the family spending and addition to savings are related is
a. 3.27
b. -0.58
c. -0.63
d. -0.92
10. The p-value for testing whether the family spending and addition to savings are related is:.
a. less than 0.10
b. between 0.10 and 0.20
c. between 0.20 and 0.40
d. more than 0.40
11. The (positive) critical tvalue for testing whether the family spending and addition to saving are related at a 10% significance level is:.
a. 0.876
b. 2.131
c. 1.796
d. 2.121
12. The 90% confidence interval for the parameter β3extends from
a. 1.2281 to 2.3726
b. -0.9493 to 2.6510
c. -0.6796 to -0.4796
d. -2.2319 to 1.0727