23. The 2002 New York City Housing and Vacancy Survey showed a total of 59,324 rentcontrolled housing units and 236,263 rent-stabilized units built in 1947 or later. For these rental units, the probability distributions for the number of persons living in the unit are given (http://www.census.gov, January 12, 2004).

a. What is the expected value of the number of persons living in each type of unit?

b. What is the variance of the number of persons living in each type of unit?

c. Make some comparisons between the number of persons living in rent-controlled units and the number of persons living in rent-stabilized units.