Information Security Policies

Question

AIDS Cases from 1993 to 2003 

The cumulative number N of AIDS cases in thousands can be approximated by N= -2xsquared + 76x + 430, where x = 0 corresponds to the year 1993. year = 1993 cases = 422, year = 1995 cases = 565, year= 1997 cases = 677, year = 1999 cases = 762, year = 2001 cases = 844, year = 2003 cases = 930. 

(a) Use the equation to find N for each year in the table.

(b) Discuss how well this equation approximates the data.

(c) Rewrite the equation with the right side completely factored.

(d) Use your equation from part (c) to find N for each year in the table. Do your answers agree with those found in part (a)? 

Question

 An extremely bored man is sitting on a bench by the elevator on the 15th floor high-rise building, and is trying to guess how many times the elevator will be going down when it opens up, out of the next 20 times it opens on the floor he is on. The elevator operator told him that the probability of the elevator heading down the lower floors on any given time it opens on the 15th floor is about 0.45. Help him out by finding the probability that the elevator is heading down 10 times out of the next 20 times it opens.