Question

Consider the case0502 data from Sleuth3. <<< This is the data. Sleuth3 is preloaded into R studio.

Answer 1

Answer:

Consider the following calculations

Step-by-step explanation:

The complete R snippet is as follows

install.packages("Sleuth3")

library("Sleuth3")

attach(case0502)

data(case0502)

## plot

# plots

boxplot(Percent~ Judge, data=case0502,ylab="Values",

main="Boxplots of the Data",col=c(2:7,8),horizontal=TRUE)

# perform anova analysis

a<- aov(lm(Percent~ Judge,data=case0502))

#summarise the results

summary(a)

### we can use the independent sample t test here

sp<-case0502[which(case0502$Judge=="Spock's"),]

nsp<-case0502[which(case0502$Judge!="Spock's"),]

## perform the test    

t.test(sp$Percent,nsp$Percent)

The results are CHECK THE IMAGE ATTACHED

b)

> summary(a)

Df Sum Sq Mean Sq F value Pr(>F)

Judge 6 1927 321.2 6.718 6.1e-05 *** as the p value is less than 0.05 , hence there is a significant difference in the percent of women included in the 6 judges’ venires who aren’t Spock’s judge

Residuals 39 1864 47.8

---

Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

c)

t.test(sp$Percent,nsp$Percent)

  Welch Two Sample t-test

data: sp$Percent and nsp$Percent

t = -7.1597, df = 17.608, p-value = 1.303e-06 ## as the p value is less than 0.05 , hence we reject the null hypothesis in favor of alternate hypothesis and conclude that there is a significant difference in the percent of women incuded in Spock’s venires versus the percent included in the other judges’ venires combined

alternative hypothesis: true difference in means is not equal to 0

95 percent confidence interval:

-19.23999 -10.49935

sample estimates:

mean of x mean of y

14.62222 29.49189