Why R is essential for statistics in R Programming - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a vector of numbers in R.

R Programming

numbers <- c([1])

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A1, 2, 3, 4, 5

B1 2 3 4 5

C[1, 2, 3, 4, 5]

D(1, 2, 3, 4, 5)

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting commas between numbers

Using brackets or parentheses instead of commas

In R, the c() function combines values into a vector. Values must be separated by commas.

2fill in blank

medium

Complete the code to calculate the mean of a numeric vector in R.

R Programming

mean_value <- mean([1])

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Adata

Bnumbers

Cvector

Dmean

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the function name instead of the vector

Using an undefined variable

The mean() function calculates the average of the values in the vector named numbers.

3fill in blank

hard

Fix the error in the code to create a data frame with columns 'age' and 'score'.

R Programming

df <- data.frame(age = c(25, 30, 22), score = [1](80, 90, 85))

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Ac

Bvector

Cdata

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using list() instead of c()

Using undefined functions

The c() function combines values into a vector, which is needed for the 'score' column.

4fill in blank

hard

Fill both blanks to create a subset of 'df' where age is greater than 23.

R Programming

subset_df <- df[df$[1] > [2], ]

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Aage

B23

Cscore

D25

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong column name

Using a wrong comparison value

We select rows where the 'age' column is greater than 23 using df$age > 23.

5fill in blank

hard

Fill all three blanks to calculate the correlation between 'age' and 'score' in 'df'.

R Programming

correlation <- cor(df$[1], df$[2], method = [3])

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Aage

Bscore

C"pearson"

D"spearman"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping column names

Using method names without quotes

Using the wrong method

The cor() function calculates correlation between two vectors. We use 'age' and 'score' columns and the 'pearson' method.