Steps, Calculations and Answers
Use the following information to answer questions 1-3.
Row 1: 5, 6, 5, 8, 5, 3, 9, 11, 10, 9,
Row 2: -5.0, -4.0, -3.5, -4.1, -2.4, -2.0, -5.0, -7.2, -5.6, -6.4
1. Using row 1 of the table above for the x-values and row 2 for the y-values, find the value of
the correlation coefficient, r.
2. Using row 2 of the table above for the x-values and row 1 for the y-values, find the value of
the correlation coefficient, r.
3. What do you conclude from the results for problems 1 and 2?
Use the table below to answer questions 4-8. The table shows the ages of 13 electrical engineers
and the annual salaries (in thousands of dollars).
For this problem, it is recommended that you review the TI calculator command: Lin-
Reg(ax+b). See also page 132 of the calculator section of the technology manual.
Age, x | 22, 25, 29, 34, 39, 43, 48, 53, 56, 61, 64, 67, 69
Salary, y | 54, 57, 61, 65, 69, 72, 74, 74, 79, 79, 82, 89, 89
4. What is the correlation coefficient, r?
5. What can we conclude from the value of r?
6. What is the regression equation?
7. If possible, predict the salary for a 45 year old electrical engineer.
8. if possible predict the salary for 72 year old engineer.
Use the box-and-whisker plot below to answer questions 9-11.
9. Find the probability that a randomly selected data value is less than $24.
10. Find the probability that a randomly selected data value is between $16 and $24.
11. Find the probability that a randomly selected data value is $28 or more.
Use the following information to answer questions 12-14.
Blood Types The probability that a person in the United States has type O+ blood is 32%.
Three unrelated people in the United States are selected at random.
12. Find the probability that all three have type O+ blood.
13. Find the probability that none of the three has type O+ type blood.
14. Find the probability that at least one of the three has type O+ type blood.
Use the following information to answer questions 15-17.
Bookbinding Defects A printing company's bookbinding machine has a probability of 0:003 of producing a defective book. The machine is used to bind 3 books.
15. Find the probability that none of the books is defective.
16. Find the probability that at least one of the books is defective.
17. Find the probability that all of the books are defective.
Use the following information to answer questions 18 and 19.
Birthdays Four people are selected at random. Assume 365 days in a year.
18. What is the probability that all four share the same birthday?
19. What is the probability that none of the four shares the same birthday?