1.A 1989 study by Parl et al. (Breast Cancer Res Tr; 14:57-64) showed an association between a polymorphism in the estrogen receptor gene and the age of onset of breast cancer. The data is in the data set polymorphism.dta. There are three genotypes: 1.6/1.6, 1.6/0.7 and 0.7/0.7. The numbers refer to the size of a PvuII restriction fragment in kilobases.

Data sheet link: https://docs.google.com/spreadsheets/d/14E_L0lv2eFaldsOItUrdDaF93P_S21w2gx2xIl6ru64/edit?usp=sharing

If you are using a statistical software, please show your work. Please provide a step-by-step explanation and do not copy and paste from other sources. Thanks.

A. Perform ANOVA to compare the three genotypes with age of onset as the response.

What is the p-value for Bartlett's test for equal variances?

Is it necessary that the variances be roughly equivalent to perform ANOVA?

B. What is the p-value of the F test that compares the between groups and within groups variances?

p-value =

What is the F value?

What can you conclude?

Example: Because p < .0001, the results are significant.

C. What is the Bonferroni-corrected p-value (from software) for each of the following pairwise comparisons?

Which one is correct from the values below? If none are correct, please give the correct answers. Thanks.

1.6/1.6 to 1.6/0.7: -1.000 (or 1.0)

1.6/1.6 to 0.7/0/7: -0.0065 (or 0.018)

1.6/0.7 to 0.7/0.7: -0.0015 (or 0.004)

D. What genotype (if any) is different from the others in terms of age of onset?