7. Consider the setting and data of Exercise 6. (a) Use hand calculations to conduct the Kruskal-Wallis test at level = 0.05, stating any

7. Consider the setting and data of Exercise 6.

(a) Use hand calculations to conduct the Kruskal-Wallis test at level α = 0.05, stating any assumptions needed for its validity. (Hint. This data set has ties. You may use attach(pc); ranks=rank(values);

vranks=var(ranks); rms= by(ranks, temp, mean) to compute S2 KW and the rank averages.)

(b) Use R commands to conduct the Kruskal-Wallis test.

Report the value of the test statistic, the p-value, and whether or not the null hypothesis is rejected at level

α = 0.05.