According to a recent government report the aging of the US

According to a recent government report, the aging of the U.S. population is translating into many more visits to doctors\' offices and hospitals (USA Today, August 7, 2008). It is estimated that an average person makes four visits a year to doctors\' offices and hospitals. a. What is the mean and standard deviation of an average person\'s number of monthly visits to doctors\' offices and hospitals? b. What is the probability that an average person does not make any monthly visits to doctors\' offices and hospitals? c. What is the probability that an average person makes at least one monthly visit to doctors\' offices and hospitals?

Solution

X no of visits is Poisson with mean = variance

a) Mean of an average person number of visits per month = 4/12 =0.33

Std dev = 0.5744

b) P(X=0) = Poisson prob for 0 when mean = 0.33

= 0.7189

c) P(X>=1) = 1-P(X=0)

= 0.2811