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QUESTION The length of time a customer is in a queue waiting to be
served
at a certain cash point has cdf $F(x)=1-pe^{-\lambda x}, x \geq
0, \lambda >0,0$0. Hence
find the mean and the variance of the queueing time.
ANSWER
$F(x)=1-pe^{-\lambda x}\ \ x \geq 0, \lambda >0, 0