# statistics math help unit 4

**Question description**

Use attached Excel file "Salary Data" to answer questions.

Directions:

1. Open your Excel with PhStat2

2. Click File—Open

3. Select the **Salary
Data** file

·
Not all
questions require the use of technology or the **Salary Date** file.

· You may insert your answers, including any charts, graphs, or output, on this document.

1. For each the
following variables from the **Salary Data
Set** provide the measures of location and measures of dispersion for the
following variables:

a.Previous Experience

b.Education

c.Which variable has the greatest relative variability?

2. You are the manager of a high-end ladies fashion
store. For the past few months you have
been gathering data and found that 45% of persons entering the store actually
make a purchase. Assume these data follow **a
Binomial Distribution** and use **Excel**
to calculate the following **binomial probabilities**:

a.If 15 people enter the store, what is the probability that 9 of them will make a purchase?

b.What is the probability that at least 6 of the 15 people will make a purchase?

3. Using the **Salary
Data Set** what is the probability of randomly selecting one individual (male
or female) with a ** current annual
salary** of over $55,000?

4. The time required to complete a project is normally
distributed with a mean of 80 weeks and a standard deviation of 5 weeks. The construction company must pay a penalty
if the project is not finished by the due date of the contract. If a
construction company bidding on this contract wishes to be 90 percent sure of
finishing by the due date, use the **NORMINV
Excel Function** to determine what due date (project week #) should be
negotiated?

5. In a state lottery participants select 6 numbers between
1 and 49. At the end of the week, the state lottery commission randomly draws 6
numbers between 1 and 49. How many different possible winning number ** combinations** could be drawn by
the lottery commission?

6. From the **Salary
Data Set** and assuming that the salary data is a random sample from the
population of salaries from the multi-national company use the 90% confidence
level in PHStat to estimate the ** mean current
salary for company executives**.

a.The 90% confidence level is:

b.If you were to change the confidence level to 95%, what would happen to the confidence interval?

7. Using the **Salary
Data Set**,

a. Create a

scatter plotto show this relationship between education and beginning salary

b. Determine the

between the variablescorrelation

8. Explain why rejecting the null hypothesis does not make the alternative hypothesis true.

9. What is the purpose of statistical inference?

10. What is the difference between sampling error and the standard error of the mean?

11. You are a
consultant working for Kaplan Consulting. The Director of Human Resources for a
multi-national company has requested help in investigating a pay discrimination
complaint brought by a female executive. The company provided the data in the **Salary Data Set**. ** Use PHStat** and the appropriate t test, to investigate the
claim of pay discrimination in the current salaries. Be sure to include:

a.Your null and alternative hypotheses;

b.The level of alpha you elect to use andwhy in terms of Type I or Type II error;

c.Show the output from the analysis;

d.Your interpretation of the results; and

e.A written statement to the director of Human Resources as to whether they should be concerned about the complaint.

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