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

Given data- mean u = 9 years. exponentially As the problem distributed, then Given is f (x) u е. Then e2-0 becomes * 2 9 fax) I 9 с. a laptop works effectively a) Probability that morrethan 6 years i.e., P (x > 6 ) 6. s f(x).dx - lax jota da 6. -1/48 no I e ] 14 6. 2 to tela -619 P(1>c) - e = 0.5134 probability P(x>6) = 0.5134=é -619 b) Probability that 80% of computers Pants asting years! pot ve { x) = 0.80 j.e., Ielax da = 0.80 She HIM 0 -"Q? =0.80 [i-e143] 1- 0.8 e-lax elax 0.2 -la x = loge (0.2) x= 14.48 years 80% parts of a laptop last for 14:48 Years