Suppose you get 16 certain fuses from Target, and suppose that the life of each fuse follows a normal distribution with mean 3 years and standard deviation 0.2 years. Find the chance that the average life of those 16 fuses is greater than 3.3 years. Solution The probability is P(xbar>3.3) =P((xbar-mean)/(s/vn) >(3.3-3)/(0.2/4)) =P(Z>6) =0 (From standard normal table).

1. Suppose you get 16 certain fuses from Target, and suppose that the life of each fuse follows a
normal distribution with mean 3 years and standard deviation 0.2 years. Find the chance that the
average life of those 16 fuses is greater than 3.3 years.
Solution
The probability is
P(xbar>3.3)
=P((xbar-mean)/(s/vn) >(3.3-3)/(0.2/4))
=P(Z>6)
=0 (From standard normal table)