Question

2. On the average, a certain type of laptop works effectively for nine years. The length of time this certain laptop works effectively is exponentially distributed. a) (5%) What is the probability that a the laptop work effectively more than 6 years? b) (8%) Eighty percent of computer parts last at most how long?

Answer 1

b) 80% last more than how many years let the 80% of the computer parts last Atmost than 8 years. P(739) = 0.8

P r s 7 증 da e =0.8 Р Blo e - ) 2 / 2 = 0.8 olo »-(e) =0.8 =0.8 => acé - clo clo = 0.3 e Taking en on both sides, we get en el en 0.2 >> alo = -1.609 - P = 14.48 years
a) The probability that the laptop will work effectively for more than 6 years is 0.5134.

b) Eighty percent of the computer parts will last atmost 14.48 years.