Introduction to Regression Models

Question 1
Marks : +2 | -2
Pass Ratio : 33%
Point out the correct statement.
The mean is a measure of central tendency of the data
Empirical mean is related to “centering” the random variables
The empirical standard deviation is a measure of spread
All of the mentioned
Explanation:
The process of centering and scaling the data is called “normalizing” the data.
Question 2
Marks : +2 | -2
Pass Ratio : 33%
Minimizing the likelihood is the same as maximizing -2 log likelihood.
True
False
Explanation:
Maximizing the likelihood is the same as minimizing 2 log likelihood.
Question 3
Marks : +2 | -2
Pass Ratio : 33%
Which of the following is correct with respect to residuals?
Positive residuals are above the line, negative residuals are below
Positive residuals are below the line, negative residuals are above
Positive residuals and negative residuals are below the line
All of the mentioned
Explanation:
Residuals can be thought of as the outcome with the linear association of the predictor removed.
Question 4
Marks : +2 | -2
Pass Ratio : 33%
Point out the wrong statement.
Regression through the origin yields an equivalent slope if you center the data first
Normalizing variables results in the slope being the correlation
Least squares is not an estimation tool
None of the mentioned
Explanation:
Least squares is an estimation tool.
Question 5
Marks : +2 | -2
Pass Ratio : 33%
Which of the following refers to the circumstance in which the variability of a variable is unequal across the range of values of a second variable that predicts it?
Heterogeneity
Heteroskedasticity
Heteroelasticty
None of the mentioned
Explanation:
Heteroskedasticity has serious consequences for the OLS estimator.
Question 6
Marks : +2 | -2
Pass Ratio : 33%
Which of the following function can be replaced with the question mark in the below figure?
boxplot
lplot
levelplot
all of the mentioned
Explanation:
levelplot is used plotting “image”.
Question 7
Marks : +2 | -2
Pass Ratio : 33%
Normalized data are centered at ___ and have units equal to standard deviations of the original data.
0
5
1
10
Explanation:
In statistics and applications of statistics, normalization can have a range of meanings.
Question 8
Marks : +2 | -2
Pass Ratio : 33%
Which of the following implies no relationship with respect to correlation?
Cor(X, Y) = 1
Cor(X, Y) = 0
Cor(X, Y) = 2
All of the mentioned
Explanation:
Correlation is a statistical technique that can show whether and how strongly pairs of variables are related.
Question 9
Marks : +2 | -2
Pass Ratio : 67%
Residuals are useful for investigating best model fit.
True
False
Explanation:
Residuals are useful for investigating poor model fit.
Question 10
Marks : +2 | -2
Pass Ratio : 33%
Which of the following outcome is odd man out in the below figure?
R Squared
Kappa
RMSE
All of the mentioned
Explanation:
Kappa is categorical outcome.