Determine the mean for this discrete probability

Determine the mean for this discrete probability distribution.
3 4
0.42

5) A manager at a local company asked his employees how many times they had given blood in
the last year. The results of the survey are given below. The random variable x represents the
number of times a person gave blood and P(x) represents the probability of selecting an
employee who had given blood that percent of the time. What is the standard deviation for
the number of times a person gave blood based on this survey?
5 6
0.02
6) Sixty-five percent of men consider themselves knowledgeable soccer fans. If 10 men are
randomly selected, find the probability that exactly three of them will consider themselves
knowledgeable fans.
7) According to insurance records, a car with a certain protection system will be recovered 92%
of the time. If 800 stolen cars are randomly selected, what is the mean and standard deviation
of the number of cars recovered after being stolen?
8) Find the area under the standard normal curve to the left of z = 1.5. Area is .9332.

9) Find the area under the standard normal curve to the right of z =-1.25. Area from table is .1056.
10) Find the area under the standard normal curve between z = 1 and z = 2.
Look up a z of 2. Area is .9772.
11) The tread life of a particular brand of tire is a random variable best described by a normal
distribution with a mean of 60,000 miles and a standard deviation of 2900 miles. What is the
probability a particular tire of this brand will last longer than 57,100 miles?
Look up a z of -1 on the standard normal table. Then, subtract your answer from 1. Area is .1587. Our
12) The length of time it takes college students to find a parking spot in the library parking lot
follows a normal distribution with a mean of 6.5 minutes and a standard deviation of 1
minute. Find the probability that a randomly selected college student will take between 5.0
and 7.5 minutes to find a parking spot in the library lot.
Look up a z of -1.5 and a z of 1.
13) A new phone system was installed last year to help reduce the expense of personal calls that
were being made by employees. Before the new system was installed, the amount being spent
on personal calls follows a normal distribution with an average of $900 per month and a
standard deviation of $50 per month. Refer to such expenses as PCEʹs (personal call expenses).
Find the probability that a randomly selected month had a PCE that falls below $750.