Kapitel 6-7

Axel Duvebäck & David Sivén

require(mosaic)

6.01

D

6.02

1. Response: salary Explanatory: sex

2. Response: salary Explanatory: years.experience

3. Response: promoted Explanatory: race

4. Response: laid.off Explanatory: age

7.01

a) Intercept: 3 z coef: 17 y coef: 4 x coef: -7

b) Intercept: 1.22 educ coef: 0.27 age coef: 0.12 age:educ coef: 0.04

c) Intercept: 8 colorRed coef: 3 colorBlue: -4

7.05

cps = fetchData("CPS85")
swim = fetchData("swim100m.csv")
utils = fetchData("utilities.csv")
feet = fetchData("KidsFeet")

a) 32

lm(age ~ married - 1, data = cps)

Call:
lm(formula = age ~ married - 1, data = cps)

Coefficients:
marriedMarried   marriedSingle  
          39.2            32.3  

b) C

lm(age ~ married, data = cps)

Call:
lm(formula = age ~ married, data = cps)

Coefficients:
  (Intercept)  marriedSingle  
        39.20          -6.88  

c) 65

lm(time ~ sex - 1, data = swim)

Call:
lm(formula = time ~ sex - 1, data = swim)

Coefficients:
sexF  sexM  
65.2  54.7  

d) -150

lm(ccf ~ as.factor(month), data = utils)

Call:
lm(formula = ccf ~ as.factor(month), data = utils)

Coefficients:
       (Intercept)   as.factor(month)2   as.factor(month)3  
           192.000               2.375             -62.250  
 as.factor(month)4   as.factor(month)5   as.factor(month)6  
          -113.625            -141.625            -178.111  
 as.factor(month)7   as.factor(month)8   as.factor(month)9  
          -182.667            -180.333            -176.556  
as.factor(month)10  as.factor(month)11  as.factor(month)12  
          -149.875             -88.778              -0.875  

7.10

a) B

b) B

c) E

7.11

a) -0.2599

b) -0.324

c) 0.174

7.14

a) A

b) A

c) C