In a clinical trial of Lovastatin (a cholesterol-reducing drug), investigators for a drug company studied the question of whether using Lovastatin increased the risk of skin infections. They recorded the following frequencies of infection in three treatment groups and a control group

Placebo Lovastatin 10mg Lovastatin 20mg Lovastatin 40mg

Infection 14 23 31 16

No Infection 243 251 255 187

Use the data in this contingency table to test the claim, at the 1% significance level that getting an infection is independent of the treatment.

(a) State your hypotheses clearly and precisely.

(b) Calculate the test statistic from the data.

(c) Find the p-value for the test.

(d) State your decision, and how you arrived at it.

(e) State is your conclusion.