Recent content by tiffyuyu

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...