During the period of time that a local university takes phone-in registrations, calls come in at the rate of one every two minutes.

1. what is the expected number of calls in one hour?
2. what is the probability of three calls in five minutes (to 4 decimals)?
3. what is the probability of no calls in a five-minute period (to 4 decimals)?

30, 0.2138,0.0821

Step-by-step explanation:

Given that during  the period of time that a local university takes phone-in registrations, calls come in at the rate of one every two minutes.

Hence in one hour expected calls = 60/2 = 30

1)  the expected number of calls in one hour=30

2) the probability of three calls in five minutes

In 5 minutes average is 2.5

This is a Poisson process

P(X=3) = 0.2138

3)  the probability of no calls in a five-minute period

= P(X=0) = 0.0821

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.