Regression 1 + 2 || with 100% Errorless Answers.
The WAIS intelligence quotient (IQ) is normally distributed with a mean of 100 and a standard
deviation of 15. If an IQ between 85 and 115 is deemed normal, what percentage
(approximately) of the general population would be considered normal?
(A) 30%
(B) 50%
(C) 70%
(D) 90% correct answers (C) 70%
In the four bivariate relationships given below, in terms of Pearson product-moment correlations
(r), the strongest relationship is the one for which r is:
(A) .69.
(B) -.70.
(C) -.10.
(D) .01. correct answers (B) -.70.
In correlational analysis, skewed variables are transformed to be normally distributed because
(A) this increases the relationship between variables.
(B) this decreases the relationship between variables.
(C) this removes the effect of influential points.
(D) this might invalidate the test. correct answers (D) this might invalidate the test.
Which one of the following does not increase the power of a test of r between X and Y?
(A) Standardising the scores of X and Y.
(B) Adopting a larger Type I error rate.
(C) Conducting a one-tailed test instead of a two-tailed test.
(D) Increasing the magnitude of r. correct answers (A) Standardising the scores of X and Y.
, In clinical trials, it is ethically responsible to use a sample size that is sufficient to detect an
effect but not too large as to inconvenienced the patients any longer than necessary. Which
sample size should the researcher use to ensure that she has sufficient power?
(A) N = 15 (power of .70)
(B) N = 22 (power of .80)
(C) N = 30 (power of .90)
(D) N = 37 (power of .95) correct answers (B) N = 22 (power of .80)
A scatterplot of the residuals is NOT used to check for:
(A) normality of distribution of errors.
(B) the relationship between variables.
(C) the presence of influential cases.
(D) homogeneity of variance of errors. correct answers (B) the relationship between variables.
When values of X do not exactly predict values of Y, the R2 value is:
(A) less than 0.
(B) 0.
(C) somewhere between 0 and 1.
(D) 1.
*when they say do not exactly predict, it means it did not predict fully of y. correct answers (C)
somewhere between 0 and 1.
Which case will not be considered an influential in a regression of Y on X?
(A) A case with a mean of X and a large Y.
(B) A case with a small X and a mean of Y.
(C) A case with a large X and a small Y.
(D) A case with a mean of X and a mean of Y. correct answers (D) A case with a mean of X and
a mean of Y.
The WAIS intelligence quotient (IQ) is normally distributed with a mean of 100 and a standard
deviation of 15. If an IQ between 85 and 115 is deemed normal, what percentage
(approximately) of the general population would be considered normal?
(A) 30%
(B) 50%
(C) 70%
(D) 90% correct answers (C) 70%
In the four bivariate relationships given below, in terms of Pearson product-moment correlations
(r), the strongest relationship is the one for which r is:
(A) .69.
(B) -.70.
(C) -.10.
(D) .01. correct answers (B) -.70.
In correlational analysis, skewed variables are transformed to be normally distributed because
(A) this increases the relationship between variables.
(B) this decreases the relationship between variables.
(C) this removes the effect of influential points.
(D) this might invalidate the test. correct answers (D) this might invalidate the test.
Which one of the following does not increase the power of a test of r between X and Y?
(A) Standardising the scores of X and Y.
(B) Adopting a larger Type I error rate.
(C) Conducting a one-tailed test instead of a two-tailed test.
(D) Increasing the magnitude of r. correct answers (A) Standardising the scores of X and Y.
, In clinical trials, it is ethically responsible to use a sample size that is sufficient to detect an
effect but not too large as to inconvenienced the patients any longer than necessary. Which
sample size should the researcher use to ensure that she has sufficient power?
(A) N = 15 (power of .70)
(B) N = 22 (power of .80)
(C) N = 30 (power of .90)
(D) N = 37 (power of .95) correct answers (B) N = 22 (power of .80)
A scatterplot of the residuals is NOT used to check for:
(A) normality of distribution of errors.
(B) the relationship between variables.
(C) the presence of influential cases.
(D) homogeneity of variance of errors. correct answers (B) the relationship between variables.
When values of X do not exactly predict values of Y, the R2 value is:
(A) less than 0.
(B) 0.
(C) somewhere between 0 and 1.
(D) 1.
*when they say do not exactly predict, it means it did not predict fully of y. correct answers (C)
somewhere between 0 and 1.
Which case will not be considered an influential in a regression of Y on X?
(A) A case with a mean of X and a large Y.
(B) A case with a small X and a mean of Y.
(C) A case with a large X and a small Y.
(D) A case with a mean of X and a mean of Y. correct answers (D) A case with a mean of X and
a mean of Y.
