Vitamin C (ascorbate) boosts the human immune system and is effective in preventing a variety of illnesses. In a study by E. Cameron and L. Pauling, published as the paper ''Supplemental Ascorbate in the Supportive Treatment of Cancer: Reevaluation of Prolongation of Survival Times in Terminal Human Cancer'' (Proceedings of the National Academy of Science USA, Vol. 75, No. 9, pp. 4538–4542), patients in advanced stages of cancer were given a vitamin C supplement. Patients were grouped according to the organ affected by cancer: stomach, bronchus, colon, ovary, or breast. The study yielded the survival times, in days, given on the WeissStats CD.

Use the technology of your choice to do the following tasks.

a. Obtain individual normal probability plots and the standard deviations of the samples.

b. Perform a residual analysis. 

c. Use your results from parts (a) and (b) to decide whether conducting a one-way ANOVA test on the data is reasonable.