Useful vector functions (length, sum, mean) in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the number of elements in the vector v.

R Programming

len <- [1](v)

Drag options to blanks, or click blank then click option'

Amean

Blength

Csum

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using sum() instead of length() to count elements.

Using mean() which calculates average, not count.

The length() function returns the number of elements in a vector.

2fill in blank

medium

Complete the code to calculate the total sum of the vector v.

R Programming

total <- [1](v)

Drag options to blanks, or click blank then click option'

Alength

Bmean

Ccount

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Using length() which counts elements, not sums them.

Using mean() which calculates average.

The sum() function adds all the numbers in the vector together.

3fill in blank

hard

Fix the error in the code to calculate the average of vector v.

R Programming

avg <- [1](v)

Drag options to blanks, or click blank then click option'

Amean

Blength

Csum

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using sum() which adds numbers but does not average.

Using length() which counts elements.

The mean() function calculates the average value of the vector.

4fill in blank

hard

Fill both blanks to create a vector with word lengths greater than 3.

R Programming

lengths <- [1](words[[2](words) > 3])

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Anchar

Blength

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Using length() which counts elements in a vector, not characters in a string.

Using sum() which adds numbers, not counts characters.

The nchar() function returns the number of characters in a word. We use it to get length and to compare if length is greater than 3.

5fill in blank

hard

Fill all three blanks to create uppercase words with character count greater than 4.

R Programming

result <- [1](words[[2](words) [3] 4])

Drag options to blanks, or click blank then click option'

Atoupper

Bnchar

C>

Dtolower

Attempts:

3 left

💡 Hint

Common Mistakes

Using tolower() instead of toupper() for uppercase conversion.

Using length() instead of nchar() for character count.

toupper() converts words to uppercase, nchar() counts characters, and > checks if greater than 4.