Answer:
a) E(X)=1
b) σ=1
c) P(X>1)=0.368
d) P(2<X<5)=0.128
Step-by-step explanation:
We have X: "the time between two successive arrivals at the drive-up window of a local bank", exponentially distributed with λ = 1.
a) We have to compute the expected time between two successive arrivals.
The expected value for X as it is exponentially distributed is:

b) We have to compute the standard deviation of X.
The standard deviation is calculated as:

c) The probability that X is larger than 1 (P(X>1))
We can express the probability as:

d) The probability that X is between 2 and 5 (P(2<X<5))

F=x-48 over 4x. I hope that is right :)
Answer:
1/50000
Step-by-step explanation:
1/50000 is the value of 5
Answer:
no
Step-by-step explanation: