Homework answers / question archive / Question 1 The range of the correlation coefficient is? a

Question 1 The range of the correlation coefficient is? a

Statistics

Share With

---

Question 1
The range of the correlation coefficient is?
a. -1 to 0.
b. 0 to 1.
c. -1 to 1.
d. None of the above.

Question 2
Which of the following values could not represent a correlation coefficient?
a. r = 0.99
b. r = 1.09
c. r = -0.73
d. r = -1.0

Question 3
Answer questions 3 - 9 from the following problem statement.
An instructor wants to show the students that there is a linear correlation between the number of hours they spent watching TV during a certain weekend and their scores on a test taken the following Monday. The number of television viewing hours and the test scores for 12 randomly selected students are shown in Table 1.
What is value of the correlation coefficient, r?
Hours
x 0 1 2 3 3 5 5 5 6 7 7 10
Score
y 96 85 82 74 95 68 76 84 58 65 75 50
a. 0.84
b. -0.831
c. -0.952
d. 1.0

Question 4
Using Table 11 in Appendix B of the text, what is the critical value if α = 0.05?
a. 0.632
b. 0.735
c. 0.708
d. 0.576

Question 5
Which of the following is true at α = 0.05?
a. |r| > critical value
b. |r| < critical value
c. |r| = critical value
d. None of the above

Question 6
What are the null and alternative hypotheses for this given problem?
a. Ho: &#961; = 0; Ha: &#961; &#8800; 0
b. Ho: &#961; &#8805; 0; Ha: &#961; < 0
c. Ho: &#961; &#8804; 0; Ha: &#961; > 0
d. Ho: &#961; < 0; Ha: &#961; &#8805; 0

Question 7
If a hypothesis test at &#945; = 0.05, has been performed using Table 5 in Appendix B, then what are the rejection regions?
a. t < -2.447 & t > 2.447
b. t < -1.812 & t > 1.812
c. t < -2.228 & t > 2.228
d. t < -0.7 & t > 0.7

Question 8
What is the value of standardized test statistics, t?
a. -4.73
b. -5.18
c. 5.67
d. 4.03

Question 9
Which pair of conclusions is appropriate for this given problem?
a. The correlation is not significant; reject the null hypothesis.
b. The correlation is significant; reject the null hypothesis.
c. The correlation is not significant; fail to reject the null hypothesis.
d. The correlation is significant; fail to reject the null hypothesis.

Question 10
If &#375; is the predicted value for a given x-value and b is the y-intercept then the equation of a regression line for an independent variable x and a dependent variable y is
a. &#375; = mx + b, where m = slope.
b. x = &#375; + mb, where m = slope.
c. &#375; = x/m + b, where m = slope.
d. &#375; = x + mb, where m = slope.

Question 11
Answer questions 11- 14 from the following table.
The ages (in years) of seven children and number of words in their vocabulary is given in Table 2.
What is the value of slope, m of the equation of regression line for the given data?
Age, x 3 4 4 5 6 2 3
Vocabulary size, y 1100 1300 1500 2100 2600 460 1200
a. m = -504.474
b. m = -490.791
c. m = 510.789
d. m = 1300

Question 12
What is the value of y-intercept, b of the equation of regression line for the given data?
a. -504.474
b. -490.791
c. 510.789
d. 1300

Question 13
Using the regression line equation for the given data, find the value of y for x = 4.
a. 1300
b. 1400
c. 1500
d. 1539

Question 14
What is the standard error of estimate, se for this given problem?
a. 139.2
b. 141.3
c. 1143.3
d. 1541.8

Question 15
Which of the following indicates a strong positive correlation?
a. r = 0
b. r = -0.793
c. r = 0.913
d. r = 0.45

Question 16
The coefficient of determination is the
a. ratio of the explained variation to the total deviation.
b. ratio of the unexplained deviation to the explained deviation.
c. ratio of the unexplained deviation to the total variation.
d. ratio of the explained variation to the total variation.

Question 17
If the correlation coefficient r = 0.5 then the coefficient of determination is
a. 0.10
b. 0.25
c. 1.00
d. 2.50

Question 18
Which one of the following statement is false?
a. A nonparametric test is a hypothesis test.
b. A nonparametric test requires a specific condition.
c. Nonparametric tests are easier to perform than corresponding parametric tests.
d. Nonparametric tests are less efficient than parametric tests.

Question 19
Which of the following statement is true for using Wilcoxon signed-test and
Wilcoxon rank sum test?
a. If the samples are dependent we can use a Wilcoxon signed-rank test.
b. If the samples are independent we can use a Wilcoxon rank sum test.
c. None of the above.
d. Both of A & B.

Question 20
The condition(s) for using a Kruskal-Wallis test is/are
a. The sample must be randomly selected.
b. The size of each sample must be at least 10.
c. None of above.
d. Both of A & B.