Suppose that fund-raisers at a university call recent graduates to request donations for campus outreach programs. They report the following information for last year's graduates. Size of donation $0 $10 $25 $50
Proportion of call 0.40 0.30 0.25 0.05
Three attempts were made to contact each graduate. A donation of $0 was recorded both for those who were contacted but who declined to make a donation and for those who were not reached in three attempts. Consider the variable
x = amount
of donation for the population of last year's graduates of this university.
(a) Write a few sentences describing what you think you might see if the value of x was observed for each of 1000 graduates.
You would expect roughly of the graduates to donate nothing, roughly to donate $10, roughly to donate $25, and roughly to donate $50. The frequencies would be close to, but not exactly, these values. The four frequencies would add to .
(b) What is the most common value of x in this population?
$
(c) What is P(x ≥ 25)?
(d) What is P(x > 0)?