The maximum patent life for a new drug is 17 years. subtracting the length of time required by the fda for testing and approval of the drug provides the actual patent life of the drug - that is, the length of time that a company has to recover research and development costs and make a profit. suppose the distribution of the lengths of patent life for new drugs is as shown here:
years, x: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
p(x): .03, .05, .07, .10, .14, .20, .18, .12, .07, .03, .01
(a) find the expected number of years of patent life for a new drug.
(b) find the standard deviation of x.
(c) find the probability that x falls into the intervalµ ± 2σ ?