R Programming Language Certification Statistical Analysis & Modeling in R

Question 1

Which R function fits a linear regression model?

Accepted Answer

lm()

Answer

glm()

Answer

regress()

Answer

fit_linear()

Question 2

What does the summary() function return when applied to a linear model in R?

Accepted Answer

Coefficients, standard errors, t-values, p-values, and R-squared

Answer

A plot of residuals

Answer

The model formula only

Answer

A confusion matrix

Question 3

Which function performs a two-sample t-test in R?

Accepted Answer

t.test()

Answer

ttest()

Answer

mean_test()

Answer

hypothesis.test()

Question 4

What does cor() compute in R?

Accepted Answer

The correlation coefficient between two or more variables

Answer

The covariance matrix

Answer

A regression coefficient

Answer

A chi-square statistic

Question 5

Which R function performs a one-way ANOVA?

Accepted Answer

aov()

Answer

anova()

Answer

lm()

Answer

kruskal.test()

Question 6

What does the p-value represent in a hypothesis test conducted in R?

Accepted Answer

The probability of observing data at least as extreme as the sample, given the null hypothesis is true

Answer

The probability the null hypothesis is true

Answer

The effect size

Answer

The confidence interval width