Question 1

Which R package was used for the Levene's test in ANOVA and for hypothesis testing?&#10;A) library(car)&#10;B) library(caret)&#10;C) library(cluster)&#10;D) library(corrplot)

Accepted Answer

Others were:
 library(caret) # Used for logistic regression
library(cluster) # Used for cluster analysis
library(corrplot) # Used for visualizing correlation matrices

Question 2

Which R package is NOT used in conjunction with crosstabulation?&#10;A) library(expss)&#10;B) library(gmodels)&#10;C) library(plyr)&#10;D) library(vcd)

Accepted Answer

The "plyr" package which is used, for example, to apply a statistical function to each subset of a data frame. The "expss" and "gmodels" packages contain crosstabulation commands (the cro and CrossTable commands respectively). The "vcd" package supports measures of association for crosstabulation through its assocstats command. There are also other crosstabulation programs, such as xtabs from the "stats" package in R's System Library.

Question 3

Given that a data frame called &#34;survey&#34; is loaded and has a column labeled &#34;marital&#34;, what is wrong with this command?: table(marital)&#10;A) The table command requires two variables, not just one.&#10;B) Should be TABLE(survey$marital)&#10;C) Should be table:survey$marital&#10;D) Should be table(survey$marital)

Accepted Answer

is correct. A is incorrect because table does support 1-way tables, which are frequency distributions. B is incorrect because R is case-sensitive in most contexts and will not recognize the table command if capitalized. C is incorrect because commands like table require the argument in parentheses, whereas the double-colon is used in relation to packages.

Question 4

What command in R is used most frequently to implement ordinary least squares (OLS) regression? Fill In: __________________________

Accepted Answer

The answer of What command in R is used most...

Question 5

Give a short answer: What is the &#34;base::&#34; part in the command below and what does it do? base::table(survey$marital,survey$sex)

Accepted Answer

The answer of Give a short answer: What is the...

Question 6

Cronbach's alpha, a leading measure of reliability, is produced by which R package?&#10;A) reliability&#10;B) psych&#10;C) alpha&#10;D) alpha

Accepted Answer

The psych package is an important statistical package which supports the alpha command and many other statistical procedures. A is wrong because there is no package "reliability". There is a package "Reliability", but it is not used in the text and does not compute Cronbach's alpha b but rather serves specialized purposes in software reliability. C is incorrect because there is no "alpha" package. D is wrong because alpha is a command, not a package.

Question 7

Which was NOT used for cluster analysis in the text?&#10;A) clusplot from the &#34;cluster&#34; package&#10;B) cluster.stats from the &#34;fpc&#34; package&#10;C) NbClust from the &#34;NbClust&#34; package.&#10;D) All of the above were used

Accepted Answer

All were used. Also used was pmm from the "cluster" package.

Question 8

The ANOVA family has four main variants: ANOVA, ANCOVA, MANOVA, and MANCOVA. In the text, which command(s) was/were used to implement them?&#10;A) anova&#10;B) anova and manova&#10;C) aov and manova&#10;D) glm

Accepted Answer

The aov command from the "stats" package in R's System Library was used for ANOVA and ANCOVA and the manova command, also from the "stats" package, was used for MANOVA and MANCOVA. Answer A is incorrect because there is no "anova" package (there is an "Anova" package but it was only mentioned, not used, in the text). Answer B is incorrect for the same reason. Answer D is in error also: the glm command was used for logistic regression.

Question 9

In logistic regression, what is a synonym for a &#34;confusion table&#34;, created by the confusionMatrix command?&#10;A) a regression table&#10;B) a logistic regression table&#10;C) a table of logistic coefficients&#10;D) a classification table

Accepted Answer

is the correct answer. A "hit table" is another synonym. For binary logistic regression, this is a 2-b-y-2 table of predicted and observed values on the binary dependent variable. Percent accuracy is a metric based on a confusion table. Answer A is vague and is not a synonym. Answer B is also vague but could refer to the same thing as Answer C, which is not a synonym and is incorrect. The confusionMatrix command is from the "caret" package.

Question 10

The &#34;processR&#34; package implements which type of statistical analysis?&#10;A) mediation and moderation analysis, as per the work of Andrew Hayes&#10;B) correlation, as per the work of Francis Galton&#10;C) correlation, as per the work of Karl Pearson&#10;D) processR is not a statistical package

Accepted Answer

is correct. B and C refer to correlation, which is not the focus of processR. Francis Galton is credited with being the inventor of correlation, but the most widely used variant, Pearsonian correlation, was invented by Karl Pearson. Answer D is simply wrong.

Deck 2: Statistical Analytics With R Part 1