The data are from a national sample of 6000 households with a male head of household and earnings of less than $15,000 annually in 1966. Some demographic subgroups were formed for analysis of the relationship between average hours worked during the year and average hourly wages and other variables. Each data point represents one demographic subgroup.

The variables used were

? HRS: Average hours worked during the year (in hours) ? WAGE: Average hourly wage (in $) ? ASSET: Average family asset holdings (bank accounts, etc.) (in $) ? AGE: Average age of respondent (in years) ? SCHOOL: Average highest grade of school completed

Here is a summary of the variables (will be needed in multiple questions): HRS WAGE ASSET AGE SCHOOL Min. : 1985 Min. :1. 423 Min. : 1370 Min. : 22 . 40 Min. : 6. 600 ist Qu. :2096 1st Qu. :2.505 1st Qu. : 4420 ist Qu. :38.55 1st Qu. : 9. 150 Median :2134 Median :2.905 Median : 7250 Median :39.20 Median :10. 300 Mean : 2137 Mean :2.772 Mean : 6265 Mean : 39 . 35 Mean : 9.997 3rd Qu. :2186 3rd Qu. :3.010 3rd Qu. : 7832 3rd Qu. :39.95 3rd Qu. : 10. 700 Max. : 2267 Max. 3. 636 Max. : 12710 Max. : 57 . 70 Max. : 11 . 700 S . D. : 64.03 S.D. : 0 . 456 S . D. : 2913 S . D. : 4.22 S . D. : 1. 141 > round (cor (wage) , 3) HRS WAGE ASSET AGE SCHOOL HRS 1. 000 0.577 0.710 -0. 102 0.666 WAGE 0.577 1.000 0.778 0. 031 0.884 ASSET 0. 710 0.778 1.000 0.399 0.630 GE -0. 102 0.031 0.399 1.000 -0.316 SCHOOL 0. 666 0.884 0.630 -0.316 1.000 Here is a regression summary output (will be needed in multiple questions): Call : Im (formula = ASSET ~ WAGE + HRS + AGE + SCHOOL, data = temp) Residuals : Min 1Q Median 3Q Max -1686.9 -490.9 -169.4 425.3 2811.2 Coefficients Estimate Std. Error t value Pr(>Itl) (Intercept) -60533.285 6545.727 -9.248 8.31e-11 WAGE 1972. 461 1094 . 348 1. 802 0. 0804 HRS 19.478 3.528 5.520 3. 62e-06 AGE 349. 708 58. 971 5.930 1. 06e-06 SCHOOL 593. 898 505 . 466 1 . 175 0. 2482 2 Residual standard error: 1007 on 34 degrees of freedom Multiple R-squared: 0.8932, Adjusted R-squared: 0. 8806 F-statistic: 71.07 on ??? and ??? DF, p-value: 4.966e-16