I made these questions based on the Analyzing Patient Data lesson from the R programming lessons.

Question 1

Suppose you had a dataframe named df:

How could I ask R to return the 3rd and 5th rows of the dataframe?

1. df[3,5]
2. df[c(3,5)]
3. df(c(3,5),)
4. df[c(3,5),]

Question 2

With the same dataframe as above, what would the following code produce?

max(df[2:4, c(1,4)])

1. 92
2. 96
3. 78
4. 97

Misconceptions

1. Correct answer
2. They have switched rows and columns
3. Not understood that 2:4 means rows 2, 3, and 4 (not just 2 and 4)
4. Not understood that c(1,4 is different from 1:4