 # Statistics Lectures - 21

A series of free Statistics Lectures with examples & solutions in videos.

These lectures discuss various types of samples t-test.

This is page twenty-one of the series of free video lessons, "Statistics Lectures".

### Statistics - Lecture 62

Independent Samples t-Test
Example:
A statistics teacher wants to compare his two classes to see if they performs any differently on the tests he gave that semester. Class A has 25 students with an average score of 70, standard deviation 15. Class B has 20 students with an average score of 74, standard deviation 25. Using alpha 0.05, did these two classes perform differently on the tests?
1. Define Null and Alternative Hypothesis
2. State Alpha
3. Calculate Degrees of Freedom
4. State Decision Rule
5. Calculate Test Statistic
6. State Results
7. State Conclusion

### Statistics - Lecture 63

Confidence Intervals for Independent Samples t-Test
We use the Independent Samples t-Test to test if two sample means are different from one another.
After the t-Test, confidence intervals can then be constructed to estimate how large that mean difference is.

### Statistics - Lecture 64

Effect Size for Independent Samples t-Test
The effect size allows us to measure the magnitude of mean differences.

### Statistics - Lecture 65

Dependent Samples t-Test
Example:
Researches want to test a new anti-hunger weight loss pill. They have 10 people rate their hunger before and after taking the pill. Does the pill do anything? Use alpha = 0.05.

Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations. 