# Are variables interchangeable?

Can independent and dependent variables be interchangeable? Why or why not?

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#### Solution Preview

The independent variable is also called an experimental variable. It is the variable being influenced in the research in order to show the result to the dependent variable. The dependent variable is also called the response variable. It is the variable being observed in the experiment.

Dependent variables are trials that is related in a few ways. For example, in a study of the efficiency of a blood pressure medicine, one might sample from a collection of people and test the blood pressure before and after using the drug being studied. That would be two variables (before and after), but one would expect the ...

#### Solution Summary

This solution looks at the interchangeability of independent and dependent variables.

Questions from descriptive statistics, testing of hypothesis,ANOVA etc

1. The difference between the maximum and minimum observations in the sample is called

A. Sample Data

B. Sample Mean

C. Sample Range

D. Sample Interval

2. The area under the normal curve between z=0 and z=1 is ___ the area under the normal curve between z=1 and z=2.

A. Less than

B. Greater than

C. Equal to

D. A, B, or C above dependent on the value of the mean

E. A, B, or C above dependent on the value of the standard deviation

3. The width of a confidence interval will be:

A. Narrower for 99% confidence than 95% confidence

B. Wider for a sample size of 100 than for a sample size of 50

C. Narrower for 90% confidence than 95% confidence

D. Wider when the sample standard deviation(s) is small than when s is large.

E. None of the above.

4. Which statement is true?

A. The correlation analysis and regression analysis are not related and interchangeable

B. The correlation analysis and regression analysis are related but not interchangeable

C. The correlation analysis and regression analysis are related and interchangeable

D. All of the above

5. The management of White Industries is considering a new method of assembling its golf car. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using the .10 level of significance, answer the following 2 questions:

a. What is the null and alternative hypothesis? is the assembly time using the new method faster?

A. H0: μ ≤ 42.3 H1: μ > 42.3

B. H0: μ = 42.3 H1: μ ≠ 42.3

C. H0: μ ≥ 42.3 H1: μ < 42.3

D. H0: μ ≤ 42.3 H1: μ < 42.3

b. Which of the following is a true statement (Use Q5) ?

A. Accept the null hypothesis

B. Accept the alternative hypothesis

C. The t value is -1.237

D. This is a two tailed test

6. Non-parametric statistics are a branch of statistics that are applied when:

A. the population is random

B. the population or sample is not normal or severely skewed

C. the population is interviewed by phone

D. non-parametric is not a branch of statistics

7. A pie chart shows the market shares of Cola products. The "slice" for Pepsi-Cola has a central angle of 90 degrees. What is their market share?

A. 100%

B. 25%

C. 50%

D. 40%

8. What would one like to know when making inference about the population based on sample data for the linear regression model?

A. If the relationship describe by the regression equation is meaningful

B. How well the equation enables one to predict values of the dependent variable

C. How useful the predictions are for decision making

D. All of the above

9. The coefficient of correlation can be in the range:

A. Between 0 and +1 (including 0 and +1)

B. Between -1 and 0 (including -1 and 0)

C. Between -1 and +1 (excluding 0)

D. Between -1 and +1 (including -1 and +1)

10. What model is used for Forecasting?

A. ANOVA

B. Regression

C. Correlation

D. Non-Parametric

11. What does the Z- test consist of?

A. Less than 30 samples

B. More than 30 samples

C. Equal to 30 samples

D. None of the above

12. A hypothesis is a statement about:

A. An experiment

B. A population

C. A sample

D. An evaluation of a reason

13. Your manager came to you to ask you to predict the sales volume for the next three months. Which tool would you utilize?

A. Anova

B. Chi-squared analysis

C. T-test

D. Forcasting

14. All of the following are possible forecasting tools for your stocks except:

A. Moving Average

B. Time Series

C. Regression

D. Chi-squared

15. For a symmetrical, bell-shaped frequency distribution, what percent of the observation lie within + / - three standard deviations of the mean?

A. 68 %

B. 95 %

C. 99.7 %

D. 110%

16.Simple Linear Regression Analysis is best described as:

a. Multiple dependent variables are examined in relation to only one independent variable.

b. Multiple dependent variables are examined in relation to only multiple independent variables.

c. One dependent variable is examined in relation to only one independent variable.

d. One dependent variable is examined in relation to multiple independent variables.

Must create a clear explanation.

ANOVA TEST:

Tom is a resident of Massachusetts for the last 5 years. He wants to move to either Connecticut or New Jersey where the

median income is higher than Massachusetts. The table below shows the median income for three States for the last

five years. Prepare an ANOVA test using Excel and find out whether or not the median income among three States is

statistically significant. (Make sure your computer has Data Analysis option. If not, go to Tools,click Add-Ins,

check Access links and click ) PoPoints

Process, calculations, and detailed explanations needed.

Year Connecticut New Jersy Massachusets

2004 81,891 82,406 78,312

2003 82,517 80,577 80,247

2002 82,702 78,560 78,025

2001 75,505 75,425 71,689

2000 74,537 70,697 68,846

Explain the following:

17. Today Botox is the leading nonsurgical cosmetic treatment in the United States. According to statistics released by the American Society of Plastic Surgeons, more than 1.1 million people had Botox injections for wrinkles in 2002, a 31% increase over the previous year.

I must create comments on this statement (above) from what the student has learned from doing research and evaluation tests.

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