4.11 Chi Squared Goodness of Fit and the T-Test

This page continues and extends our understanding of hypothesis testing, the act of creating a hypothesis about what you believe about the association between variables, data sets or distributions and then running a mathematial process to test whether what you hypothesised is indeed the case. More specifically, we will look closely at two different hypothesis tests: the T-test and the Chi Squared Goodness of Fit Test.

Key Concepts

In this unit you should learn to…

  • Complete a Chi-Squared Goodness of Fit Test. 
  • Complete a 2 sample T-test. 

Essentials

1. Chi Squared Goodness of Fit (Part 1)

What is the Chi-squared Goodness of Fit Test? How do you create the null and alternative hypothesis, the degrees of freedom and the expected frequencies?

2. Chi Squared Goodness of Fit (Part 2)

We will look at two of the same examples presented in the previous video and fully complete the Goodness of Fit test in each case. 

3. Chi Squared Goodness of Fit (Part 3)

Conducting a Chi Squared GOF test involving the normal distribution and binomial distribution. 

4. T-Test: One tailed vs Two tailed 

What is a 2-sample t-test? How do you state the null and alternative hypothesis? and how do you know whether you have a one-tailed or two-tailed test?

5. Completing the T-test

In this video we will complete the t-test by comparing the significance level to the p-value for two examples. 

6. Using the GCD to find the p-value for a 2 sample t-test

TI-84
 

TI-Nspire

Casio

 

Summary

 

Test yourself

Self Checking Quiz

Practice your understanding on these quiz questions. Check your answers when you are done and read the worked solutions when you get stuck. If you find there are still some gaps in your understanding then go back to the videos above.

Exam Style Questions

The following are exam style questions on this topic that you should try on your own before checking against the video solution.

Question 1

Question 2

Question 3

MY PROGRESS

How much of 4.11 Chi Squared Goodness of Fit and the T-Test have you understood?