In regression analysis we use the Spearman rank correlation coefficient to measure and test to determine whether a relationship exists between the two variables if:
a. one or both variables may be ordinal
b. both variables are interval but the normality requirement is not met
c. both one or both variables may be ordinal and both variables are interval but the normality requirement is not met
d. neither one or both variables may be ordinal nor both variables are interval but the normality requirement is not met
e. none of these
Q. 2If the plot of the residuals is fan shaped, which assumption of regression analysis if violated?
a. Normality.
b. Homoscedasticity.
c. Independence of errors.
d. No assumptions are violated, the graph should resemble a fan.
e. All of these.
Q. 3In order to predict with 98 confidence the expected value of y for a given value of x in a simple linear regression problem, a random sample of 15 observations is taken. Which of the following t-table values listed below would be used?
a. 1.350
b. 1.771
c. 2.160
d. 2.650
e. 1.750
Q. 4In order to predict with 80 confidence the expected value of y for a given value of x in a simple linear regression problem, a random sample of 15 observations is taken. Which of the following t-table values listed below would be used?
a. 1.350
b. 1.771
c. 2.160
d. 2.650
e. 2.260
Q. 5The width of the confidence interval estimate for the predicted value of y depends on:
a. the standard error of the estimate
b. the value of x for which the prediction is being made
c. the sample size
d. all of these
e. none of these
Q. 6In order to predict with 99 confidence the expected value of y for a given value of x in a simple linear regression problem, a random sample of 10 observations is taken. Which of the following t-table values listed below would be used?
a. 1.860
b. 2.306
c. 2.896
d. 3.355
e. 2.355
Q. 7The confidence interval estimate of the expected value of y for a given value y x, compared to the prediction interval of y for the same given value of x and confidence level, will be:
a. wider
b. narrower
c. the same
d. impossible to know
Quick Reply
