We define random variable X to be the number of parts that a…

We define rаndоm vаriаble X tо be the number оf parts that arrive at an environmental testing station in a 1-hour period.   Historical data shows that the mean number of these parts that arrive in a 1-hour period is equal to 29 and X is a Poisson random variable.  This copywritten question is part of a quiz or exam at Arizona State University. It may not be reproduced or posted without the permission of Dr. Linda Chattin The probability that 20 or fewer of these parts arrive in a 30-minute period is _______.  Express your answer to four decimal places.   You must do this problem using one of these online calculators: ti84calc.com ti84calculator.io You will not receive any credit for this question if you do not use the online calculator, even if you get it right.