1. A binomial random variable has mean 14 and variance 4.2. Find the probability that it is strictly larger than 10.
2. (Distribution of Sum). The demand for the daily newspaper in a vending stall is distributed as Bin.20; :75/ on weekdays and Bin.50; :75/ on the weekend. Assuming that all days are independent, what is the distribution of the weekly demand?
3. (Distribution of Difference). The demand for the daily newspaper on a Monday in a vending stall is distributed as Bin.20; :75/ and that on a Sunday as Bin.50; :75/. Find the probability that at least 20 more newspapers are sold on a Sunday than on a Monday at this stall.
4. * (Distribution of Difference). The number of earthquakes per year in Los Angeles of magnitude greater than 4 has a mean of .5 and that in Manila, Phillipines has a mean of 1. Find the pmf of the absolute difference between the number of earthquakes of magnitude greater than 4 in the two cities and approximately calculate the mean of the absolute difference.