Question

1.

Suppose annual salaries for sales associates from Geoff's Computer Shack have a mean of $32,500 and a standard deviation of $2,500.

a.	Calculate and interpret the z-score for a sales associate who makes $36,000.
b.	Suppose that the distribution of annual salaries for sales associates at this store is bell-shaped. Use the empirical rule to calculate the percentage of sales associates with salaries between $27,500 and $37,500.
c.	Use the empirical rule to determine the percentage of sales associates with salaries less than $27,500.
d.	Still suppose that the distribution of annual salaries for sales associates at this store is bell-shaped. A sales associate makes $42,000. Should this salary be considered an outlier? Explain.

2.

Compute the measures below for the following data:

5

7

9

11

15

19

Compute the following measures:

a.	Mean
b.	Variance
c.	Standard deviation
d.	Coefficient of variation
e.	25th percentile
f.	Median
g.	75th percentile

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3.

The frequency distribution below was constructed from data collected on the quarts of soft drink consumed per week by 20 students.

	Quarts of Soft Drink	Frequency
	0−3	4
	4−7	5
	8−11	6
	12−15	3
	16−19	2

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a.	Construct a relative frequency distribution.
b.	Construct a cumulative frequency distribution.
c.	Construct a cumulative relative frequency distribution.

4.

There are two more assignments in a class before its end, and if you get an A on at least one of them, you will get an A for the semester. Your subjective assessment of your performance is

​

Event	Probability
A on paper and A on test	.25
A on paper only	.10
A on test only	.30
A on neither	.35

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a. What is the probability of getting an A on the paper?

b. What is the probability of getting an A on the test?

c. What is the probability of getting an A in the course?

d. Are the grades on the assignments independent?

5.

A corporation has 15,000 employees. Sixty-two percent of the employees are male. Twenty-three percent of the employees earn more than $30,000 a year. Eighteen percent of the employees are male and earn more than $30,000 a year.

a.	If an employee is taken at random, what is the probability that the employee is male?
b.	If an employee is taken at random, what is the probability that the employee earns more than $30,000 a year?
c.	If an employee is taken at random, what is the probability that the employee is male and earns more than $30,000 a year?
d.	If an employee is taken at random, what is the probability that the employee is male or earns more than $30,000 a year or both?
e.	The employee taken at random turns out to be male. Compute the probability that he earns more than $30,000 a year.
f.	Are being male and earning more than $30,000 a year independent?

Answer 1