A population of 100 healthy women was recruited from the internal medicine practice at UT Southwestern Medical Center from June 1 - June 30, 2000 and followed for the development of breast cancer.Twelve women developed breast cancer after each was followed for 4 years.Ten women who remained healthy were followed for 2 years and then were lost to follow-up.Five women died of heart disease after 6 years of follow-up.These five women did not develop breast cancer. The remaining womenremained healthy and were each followed for 10 years.

a.Are the 100 women who enrolled in the study members of a fixed or dynamic population?

b.Calculate the cumulative incidence of breast cancer in this population - Show your works

c.Calculate the number of person-years of observation that was accrued by this population. - Show your works

d.Calculate the incidence rate . - Show your works