The maximum patent life for a new drug is 17 years Subtracti

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

Solution

Expected number of year = Sum(xP(x)) = 7.89 years

Var = E(x^2) - (E(x))^2

Var = (Sum(x^2P(x) ) - ( Sum(xP(x))^2

Var = 66.97 - 7.89^2

Var = 4.7179

SD =sqrt(Var)

SD = 2.1721

c.

interval (mean +- 2SD)

(mean - 2SD, mean+2SD)

(7.89 - 2*2.1720 , 7.89+2*2.1721)

(3.546,12.2343)

taking interval of interger part, [4,12]

P(4 <= x <= 12) = 1 - P(x=3) - P(x=13) = 1- 0.03 - 0.01 = 0.96