Chi-squared test in R Programming - Mini Project: Build & Apply

Chi-squared Test in R

📖 Scenario: You are a researcher studying if two categorical variables are related. For example, you want to check if gender and preference for a product are independent.

🎯 Goal: Build a simple R program that creates a contingency table, sets up a significance level, performs a chi-squared test, and prints the test result.

📋 What You'll Learn

Create a contingency table with exact counts

Set a significance level variable

Perform a chi-squared test using the table

Print the test result

💡 Why This Matters

🌍 Real World

Chi-squared tests are used in research to check if two categories are related, like gender and product preference.

💼 Career

Data analysts and scientists use chi-squared tests to analyze survey data and make decisions based on categorical data relationships.

1

Create the contingency table

Create a matrix called data_matrix with these exact values and dimensions: 2 rows and 2 columns. The values are 30, 10 in the first row and 20, 40 in the second row. Set the row names to c("Male", "Female") and column names to c("Like", "Dislike").

R Programming

# Create the matrix data_matrix with given values and row/column names
# Your code here

Need a hint?

Use matrix() with byrow = TRUE to fill rows first. Then assign row and column names with rownames() and colnames().

2

Set the significance level

Create a variable called alpha and set it to 0.05 to represent the significance level for the test.

R Programming

data_matrix <- matrix(c(30, 10, 20, 40), nrow = 2, byrow = TRUE)
rownames(data_matrix) <- c("Male", "Female")
colnames(data_matrix) <- c("Like", "Dislike")
# Create alpha variable and set to 0.05
# Your code here

Need a hint?

Just assign 0.05 to a variable named alpha.

3

Perform the chi-squared test

Use the chisq.test() function on data_matrix and save the result in a variable called test_result.

R Programming

data_matrix <- matrix(c(30, 10, 20, 40), nrow = 2, byrow = TRUE)
rownames(data_matrix) <- c("Male", "Female")
colnames(data_matrix) <- c("Like", "Dislike")
alpha <- 0.05
# Perform chi-squared test and save to test_result
# Your code here

Need a hint?

Use chisq.test() with the matrix as input and assign the output to test_result.

4

Print the test result

Print the variable test_result to display the chi-squared test output.

R Programming

data_matrix <- matrix(c(30, 10, 20, 40), nrow = 2, byrow = TRUE)
rownames(data_matrix) <- c("Male", "Female")
colnames(data_matrix) <- c("Like", "Dislike")
alpha <- 0.05
test_result <- chisq.test(data_matrix)
# Print the test_result
# Your code here

Need a hint?

Use print(test_result) to show the test output.