In: Statistics and Probability
Osteosarcoma is a relatively rare type of bone cancer. It occurs most often in young adults, age 10 - 19; it is diagnosed in approximately 8 per 1,000,000 individuals per year in that age group. In New York City (including all five boroughs), the number of young adults in this age range is approximately 1,400,000.
a) What is the expected number of cases of osteosarcoma in NYC
in a given year?
b) What is the probability that 15 or more cases will be diagnosed
in a given year?
c) The largest concentration of young adults in NYC is in the
borough of Brooklyn, where the population in that age range is
approximately 450,000. What is the probability of 10 or more cases
in Brooklyn in a given year?
d) Suppose that in a given year, 10 cases of osteosarcoma were
observed in NYC, with all 10 cases occurring among young adults
living in Brooklyn. An official from the NYC Public Health
Department claims that the probability of this event (that is, the
probability of 10 or more cases being observed, and all of them
occurring in Brooklyn) is what was calculated in part c). Is the
official correct? Explain your answer. You may assume that your
answer to part c) is correct. This question can be answered without
doing any calculations.
e) Suppose that over five years, there was one year in which 10 or
more cases of osteosarcoma were observed in Brooklyn. Is the
probability of this event equal to the probability calculated in
part c)? Explain your answer.