Need help with the following, it's practice for an upcoming test.

1. A frequency distribution of speeds on a road is presented in the table.

Speed (Miles per hour) Frequency (fi) Midpoint (Mi)

40 - 49 20 50 - 59 80

60 - 69 300 70 - 79 350

80 - 89 150

90 - 99 25

a. Calculate the arithmetic mean of the speed of cars traveling on that road.

2. A sports club has the following data on age and gym utilization:

Gym Utilization

Uses it Does not use it

Gender

Male 200 225 Female 275 300

a. What is the probability of finding a person who uses it and of the female gender?

b. If a client is of the male gender, what is the probability that he/she will not use it?

c. What is the probability that he/she does not use it or is female?

d. What is the probability that he is male?

e. What is the probability that he does not use the gym?

3. The following table gives the ages of the population of the United States (The World Almanac 2004). The data are in millions of people.

Age Quantity

19 and under 80.5 20-24 19.0 25-34 39.9 35-44 45.2 45-54 37.7 55-64 24.3 65 and over 35.0

Assume a random selection of one person from this population.

a. What is the probability that the person is between 20 and 24 years old?

b. That the person is between 20 and 34 years old?

c. That the person is 45 years old or older?

4. The following data represent the hourly pay received by 10 employees of a company.

11, 10, 13, 14, 15, 12, 16, 9, 8, 10

Determine:

Arithmetic mean:

Median:

Mode:

Variance:

Standard Deviation:

Coefficient of Variation: