MGSC 291 Exam 1 University of South
Carolina Exam Questions and Answers
Graded A+
putting in a dataset - Correct answer-data<-
c(81,85,93,93,99,76,75,84,78,84,81,82,89,81,96,82,74,70,84,86,80,70,131,75,88,1
02,115,89,82,79,106)
length(data) - Correct answer-tells you how may entries are in your vector
sort(data) - Correct answer-puts data smallest to largest
summary(data) - Correct answer-returns the five number summary and the sample
mean
mean(data)
sd(data)
sum(data) - Correct answer-sample mean
sample standard deviation
adds all the elements of the vector
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,seq(1,100,1)
seq(2,100,2) - Correct answer-tells r to create the sequence of numbers from 1 to
100 by 1 (1,2,3...)
1:100 does the same thing
(2,4,6...100)
data<-read.table(file.choose(),header=TRUE)
read.cvs - Correct answer-calls this dataset into r and you can name it whatever
you want
getwd() - Correct answer-creates the current working directory and calls in your
data too
dim(data) - Correct answer-checks dimensions of data
data - Correct answer-type the name of the data to see it
data[1:5] - Correct answer-calls in the first five rows of the dataset if you are
working with a large dataset
head(data) - Correct answer-shows the first few rows
data[,1:2] - Correct answer-all rows for columns 1 and 2
data[1:5,1:2] - Correct answer-first five rows and first two columns
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, str(data) - Correct answer-structure of the object
View(data) - Correct answer-(capital V) puts your data in a viewable popup
window
data$shoes - Correct answer-calls in the column called shoes
attach(data) - Correct answer-attaches data so you can work with it and don't have
to keep calling it in
(if you attach several datasets that have the same column names r will be confused
so you have to detach before attaching again)
data<-subset(data,Type=="WT") - Correct answer-you can pick out certain
rows/columns and you can enter more == and "" in order to be more specific
hist(data) - Correct answer-give you a histogram
hist(data,breaks=c(60,70,80,90)) - Correct answer-creates a sequence and breaks
them
xlab="percents of ..." - Correct answer-x axis name
ylab="Frequency" - Correct answer-y axis name
main="..." - Correct answer-title of the graph
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
Carolina Exam Questions and Answers
Graded A+
putting in a dataset - Correct answer-data<-
c(81,85,93,93,99,76,75,84,78,84,81,82,89,81,96,82,74,70,84,86,80,70,131,75,88,1
02,115,89,82,79,106)
length(data) - Correct answer-tells you how may entries are in your vector
sort(data) - Correct answer-puts data smallest to largest
summary(data) - Correct answer-returns the five number summary and the sample
mean
mean(data)
sd(data)
sum(data) - Correct answer-sample mean
sample standard deviation
adds all the elements of the vector
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,seq(1,100,1)
seq(2,100,2) - Correct answer-tells r to create the sequence of numbers from 1 to
100 by 1 (1,2,3...)
1:100 does the same thing
(2,4,6...100)
data<-read.table(file.choose(),header=TRUE)
read.cvs - Correct answer-calls this dataset into r and you can name it whatever
you want
getwd() - Correct answer-creates the current working directory and calls in your
data too
dim(data) - Correct answer-checks dimensions of data
data - Correct answer-type the name of the data to see it
data[1:5] - Correct answer-calls in the first five rows of the dataset if you are
working with a large dataset
head(data) - Correct answer-shows the first few rows
data[,1:2] - Correct answer-all rows for columns 1 and 2
data[1:5,1:2] - Correct answer-first five rows and first two columns
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, str(data) - Correct answer-structure of the object
View(data) - Correct answer-(capital V) puts your data in a viewable popup
window
data$shoes - Correct answer-calls in the column called shoes
attach(data) - Correct answer-attaches data so you can work with it and don't have
to keep calling it in
(if you attach several datasets that have the same column names r will be confused
so you have to detach before attaching again)
data<-subset(data,Type=="WT") - Correct answer-you can pick out certain
rows/columns and you can enter more == and "" in order to be more specific
hist(data) - Correct answer-give you a histogram
hist(data,breaks=c(60,70,80,90)) - Correct answer-creates a sequence and breaks
them
xlab="percents of ..." - Correct answer-x axis name
ylab="Frequency" - Correct answer-y axis name
main="..." - Correct answer-title of the graph
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
