Scores on an examination are assumed to be normally distributed with a mean of 58 and a standard deviation of 18.
(a) What is the probability that a person taking the examination scores higher than 72?
(b) Suppose that students scoring in the top 10% of this distribution are to receive an A...
The probability density function of the lifetime of a certain type of electronic device
(measured in hours), X, is given by
f(x) = 10/x^2,
0,
x > 10;
elsewhere.
(a) Find the cumulative distribution function of X, namely F(x) and hence find
P(X > 20).
(b) What is the...