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# Task $1$

# copy original dataframe into a new one: my$\_$mtcars

# mtcars object is one of many built$-$in data sets in R$.$ So you do not need to worry about creating mtcars.

my$\_$mtcars $<-$ mtcars

# $1$: investigate my$\_$mtcars using str function. How many variables and observations are included in this dataframe?

# $2$: calculate engine displacement per cylinder and save it as a new variable 'UnitEngine' in the dataframe. Populate the two XXXX below

myCars$XXXX $<-$ myCars$XXXX$/$myCars$cyl

# $3.$ summarize the new variable 'UnitEngine': use summary function

# $---------------------------------------------------$

# Task $2$

# $4.$ create a numeric vector 'Pets' with this numbers $(1,1,1,0,0)$

# $5.$ create a numeric vector 'Order' with these numbers $(3,1,2,3,3)$

# create a numeric vector 'Siblings'

Siblings $<-$ c$(0,3,5,0,0)$

# create a numeric vector 'IDs'

IDs $<-$ c$(1,2,3,4,5)$

# $6.$ Combine those four numeric vectors together into a dataframe called 'myFriends'. You must use data.frame function

# $7.$ report the structure of the dataframe

# $8.$ summarize the dataframe. Use summary function

# list $($or print$)$ all of the values for 'IDs' variable in the dataframe

myFriends$IDs

# list all of the values for 'Pets' variable in the dataframe

# $9.$ list all of the values for 'Order' variable in the dataframe

# list all of the values for 'Siblings' variable in the dataframe

myFriends$Siblings

# # $10.$ write a code to print the values in the fifth observation of the Pets variable

## $11.$ add a vector called 'age' to 'myFriends' using cbind function. $***$ YOU MUST USE cbind FUNCTION to receive full grades.

age $<-$c$(23,21,45,21,18)$

## $12.$ define a vector called 'names' by including all the names in a vector. Add a vector 'names' to 'myFriends' using cbind function. Print the structure of 'myFriends'. What is the data type $($among: factor, numeric, logical$,$ string$)$ of the 'names'?