試題詳解

136. The minimum force required to break a particular type of cable is normally distributed with mean 12,432 and standard deviation 25. A random sample of 400 cables of this type is selected.
Calculate the probability that at least 349 of the selected cables will not break under a force of 12,400.
(A) 0.62
(B) 0.67
(C) 0.92
(D) 0.97
(E) 1.00