The number of days, X, that it takes the post office to deliver a notarized letter cross country between City A and City B has the probability distribution align center (a) Find the expected number of days and the standard deviation of the number of days (b) A company in City A sends a notarized le...

a We use the following tabulated values to calculate the mean and standard deviation x fx xfx x 2 fx ...

The number of days, X, that it takes the post office to deliver a notarized letter cross-country

Question:

The number of days, X, that it takes the post office to deliver a notarized letter cross-country between City A and City B has the probability

(a) Find the expected number of days and the standard deviation of the number of days.
(b) A company in City A sends a notarized letter to a company in City B with a notarized return receipt request that is to be mailed immediately upon receiving the letter. Find the probability distribution of total number of days from the time the letter is mailed until the return receipt arrives back at the company in City A. Assume the two delivery times have the same distribution and are independent.
(c) A single notarized letter is sent from City A on each of 100 different days. What is the approximate probability that more than 25 of the letters take 5 days to reach City B?

Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...