Data Science

Residual Variation and Multivariate

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Residual ______ plots investigate normality of the errors.
RR
PP
QQ
None of the mentioned
Explanation:
Patterns in your residual plots generally indicate some poor aspect of model fit.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is the correct formula for total variation?
Total Variation = Residual Variation – Regression Variation
Total Variation = Residual Variation + Regression Variation
Total Variation = Residual Variation * Regression Variation
All of the mentioned
Explanation:
The complementary part of the total variation is called unexplained or residual.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Which of the following things can be accomplished with linear model?
Flexibly fit complicated functions
Uncover complex multivariate relationships
Build accurate prediction models
All of the mentioned
Explanation:
Linear models are the single most important applied statistical and machine learning technique.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The least squares estimate for the coefficient of a multivariate regression model is exactly regression through the origin with the linear relationships.
True
False
Explanation:
Multivariate regression adjusts a coefficient for the linear impact of the other variables.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of the following can be useful for diagnosing data entry errors?
hat values
dffit
resid
all of the mentioned
Explanation:
resid returns the ordinary residuals.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Point out the correct statement.
A standard error is needed to create a prediction interval
The prediction interval must incorporate the variability in the data around the line
Investors use the residual variance to measure the accuracy of their predictions on the value of an asset
All of the mentioned
Explanation:
In statistics, explained variation measures the proportion to which a mathematical model accounts for the variation of a given data set.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following show residuals divided by their standard deviations?
rstudent
cooks.distance
rstandard
all of the mentioned
Explanation:
rstandard stands for standardized residuals.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Point out the wrong statement.
The fraction of variance unexplained is an established concept in the context of linear regression
“Explained variance” is routinely used in principal component analysis
The general linear model extends simple linear regression (SLR) by adding terms linearly into the model
None of the mentioned
Explanation:
Linearity refers to a mathematical relationship or function that can be graphically represented as a straight line.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following statement is incorrect with respect to outliers?
Outliers can have varying degrees of influence
Outliers can be the result of spurious or real processes
Outliers cannot conform to the regression relationship
None of the mentioned
Explanation:
Outliers can conform to the regression relationship.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Multivariate regression estimates are exactly those having removed the linear relationship of the other variables from both the regressor and response.
True
False
Explanation:
Multivariate Data Analysis refers to any statistical technique used to analyze data that arises from more than one variable.