The lifetime in months of a transistor in a certain application is random with probability density function:

f(x) = {0.4e^-0.4x, x> 0 0, x< 0

a. compute the mean lifetime.

b. compute the standard deviation of the lifetimes.

c. compute the cumulative distribution function of the lifetime.

d. compute the probability that the lifetime will be less than 6 months.

e. compute the 60^th percentile of the lifetime.

Aprofessional hockey team has noticed that, over the past several seasons, as the number of wins increases, the total number of hot dogs sold at the concession stands increases. the hockey team concludes that winning makes people crave hot dogs. what is wrong with the hockey team's conclusion? a) it does not take into account the attendance during each season. b) it does not take into account the number of hamburgers sold during each season. c) it does not take into account the number of concession stands in the hockey arena. d) it does not take into account the number of seasons the hockey team has been in existence.