If We Plot a Continuous Probability Distribution F(x),the Total Probability

Multiple Choice

If we plot a continuous probability distribution f(x) ,the total probability under the curve is

A) -1
B) 0
C) 1
D) 100
Suppose that the number of customers arriving each hour at the only checkout counter at a local convenience store is approximately Poisson distributed with an expected arrival rate of 30 customers per hour.Let X represent the number of customers arriving per hour.The probabilities associated with X are shown below.
P(X < 5) = 0.0000,P(X < 10) = 0.0000,P(X < 15) = 0.0009,
P(X < 20) = 0.0219,P(X < 25) = 0.1572,P(X < 30) = 0.4757
P(X = 30) = 0.0726,P(X = 31) = 0.0703,P(X = 32) = 0.0659,
P(X = 33) = 0.0599,P(X = 34) = 0.0529,P(X = 35) = 0.0453