Section 9.1

1.True or False?When creating a scatter plot, the independent variable is measured on the vertical axis and the dependent variable is measured on the horizontal axis.

2.Explain.A researcher is studying the relationship between two variables. Assume the horizontal axis variable isxxand the vertical axis variable isyy. The correlation coefficient,rr, is calculated and it has a value that is negative. Reading from left-to-right, what trend should you observe in a scatter plot of the data for the two variables.

Problems 3-5Use the data sets in Table 1 to answer the questions.

Crimes,xx	Arrests,yy
1.44	0.36
1.49	0.37
1.36	0.34
1.42	0.36
1.42	0.37
1.39	0.36
1.48	0.39
1.50	0.37
1.42	0.35
1.41	0.34
1.38	0.34
1.45	0.36
1.44	0.37
1.47	0.38

3. Display the data in a scatter plot. (Please, orient the x and y-axes in the usual way.)

4. Calculate the correlation coefficient,rr(Note: use technology for the calculation; round result to 3 decimal places.).

5. What do you conclude about the type of correlation?

Section 9.2

6.Residuals.If the observedyy-value at a data point is 10 and the predictedyyvalue for that point is 6, then the residual is what value?

7. Ifx=5x=5,y=10y=10, andm=2.5m=2.5, what is the value ofbbin the regression equation.

Problems 8-11.Use the data in Table 2 to answer the questions.

xx	yy
26	58
47	110
37	82
24	51
43	101
39	83

8. What is the equation of the regression line (Round the coefficients to 3 decimal places.)?

9. Construct a scatter plot for the data showing the regression lineandthe data points on the same graph.

Problems 10-11.Use the regression equation found in question 9 to predict the value ofyyfor the values ofxxgiven. If it is not meaningful to predict the value ofyy, explain why not.

10.x=44x=44

11.x=53x=53

Section 3.1

Problems 12-13.Answer the following questions. A probability experiment is conducted by first spinning the spinner shown in Figure 2a, then spinning the spinner in figure 2b.

Figure 2a. SpinnerFigure 2b. Spinner

12. What set represents the sample space (Note: show all elements of the sample space using set notation.)

13. Draw a tree diagram for the probability experiment.

14.Multiple Choice Quiz.A multiple choice quiz has five possible answers per question. Assuming that no questions are left unanswered, in how many ways can an 8 question multiple choice quiz be answered?

15. A probability is considered unusual if it is less than what value?

16.True or False?A probability value,pp, will always be a value in the interval[0,1][0,1].

17.Probability Experiment. A probability experiment consists of spinning two spinners (Note: The spinners are the same ones in Figure 2a and Figure 2b.). What is the probability of spinning a # or a % on the first spinner, then spinning a value of 2 or 3 on the second spinner? (Note: you can assume an equal probability for any possible outcomes on either spinner.)

18. Use the frequency distribution in Table 3. Find the probability that a building resident chosen at random is between 35 and 64 years old?.

Ages of Building Residents	Frequency
18 to 20 years old	19
21 to 24 years old	37
25 to 34 years old	43
35 to 44 years old	27
45 to 64 years old	39
65 years old and over	35

19. Use the pie chart in Figure 3 to find the probability that a student attained a B or a C on the quiz? (Round results to 3 decimal places.)

Figure 3. The grades attained by students on a recent quiz.

Section 3.2

20.Classifying Events.A uniquely numbered ball is randomly selected from a bin. Then another ball is selected from the bin. Are the events for selecting the balls independent or dependent?

Problems 21-25.Use the information in Table 4 to answer the questions. Round results to 3 decimal places.

	Nursing Majors	Non-Nursing Majors	Total
Males	295	684	979
Females	422	521	943
Total	717	1205	1922

21. Find the probability that a randomly selected student is male.

22. Find the probability that a randomly selected student is non-nursing major.

23. Find the probability that a randomly selected student is a nursing major given that the student is a female.

24.Find the probability that a randomly selected student is a nursing major and female.

25. Are the events being a female student and being a non-nursing major independent or dependent events? Show the probability calculations that support your answer.