T.TEST in Excel (Table of Contents)
T.TEST in Excel
T.TEST Function is one of the Statistical function in excel. T.TEST is also one of the inferential statistics. T.TEST is very helpful to find out the significant difference between the means of two groups.
T.TEST Function “returns the probability associated with a Student’s t-Test”
In simple terms “when we have two conditions and would like to compare the differences between the two conditions and see if the difference is significant”.
Are the two things we are comparing are different from each other?
T.TEST Formula in Excel
The Formula for the T.TEST Function in Excel is as follows:
The Formula of T.TEST includes 4 types of arguments:
Array1: This is the first set of sample you are testing.
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Array2: This is the second set of sample you are comparing.
Tails: This is the number of tails for the distribution. There are two types of tails are there. 1. One-tailed distribution and 2.Two tailed distribution
Type: There are 3 types of T.Test available in statistics.
- Paired this examines whether the mean between paired sets is equal.
- Two-sample equal variance examines whether the variance of means between two sets is equal.
- Two-sample unequal variance this examines whether the variance of means between two sets is unequal.
In recent versions, T.TEST is introduced. In earlier versions, TTEST is the formula. Still, it is available in recent versions to support the compatibility.
How to Use T.TEST Function in Excel?
T.TEST Function in Excel is very simple and easy to use. Let understand the working of T.TEST in Excel by Some Examples.
The functionality of the T.TEST can be best explained by using an example dataset to get the logic of T.TEST
I have a Group 1 and Group 2 test scores of a classroom. I need to run T.TEST to find is there a significant difference between these two groups.
Apply T.TEST to get the difference.
The first test is a type of Paired.
The result is 0.04059.
The second test is a type of Two Sample equal variance.
The result is 0.2148.
The third test is a type of Two Sample unequal variance.
The result is 0.2158.
The returned value is generally called as P value. If the P value is <0.05, we can come to the conclusion that two sets of data have a different mean, otherwise, the two means are not significantly different from each other.
I have the salary numbers of two different departments. I want to find if the mean of two department’s salaries is significantly different are not.
Apply T.TEST function to see the difference.
The above formula returns the result as:
Run T.TEST using Analysis Tool Pack
We can run the T.TEST using analysis tool pack located under Data ribbon tab.
If you do not find this option in your excel follow below steps to unhide this.
Step 1: Go to File and Options
Step 2: Click on Add-Ins
Step 3: Select Excel Add-ins and click Go
Step 4: Select Analysis ToolPak and click OK.
Step 5: This must have enabled the Data Analysis Option.
Follow below Steps to Run T.TEST using Data Analysis ToolPak
Step 1: Click on Data Analysis under the Data tab.
Step 2: Scroll down find t-Test
Step 3: Click on first t-test and it will open the below dialogue box.
Step 4: Select the Variable 1 range and Variable 2 range.
Step 5: Once all the above boxes filled click on OK button.
It will show a detailed report.
This will show the mean of each data set, their variance, how many observations are taken into consideration, correlation, and P value.
One key thing we need to see here is the P value (refer B26) i.e. 0.000186102 that is way below than the expected P value of 0.05.
As long as the P value is less than the 0.05, our data is significant.
Things to Remember
- The T.TEST can accept only numerical values anything other than numerical values we get the result of #VALUE!
- If the tails value is other than 1 or 2 we will get #NUM! error
- Learn the difference between One-tailed test and Two-tailed test to understand it better.
- One of the assumptions is samples have been randomly drawn from the large data.
- Standard P-Value is 0.05 i.e. 5%. If the variance is less than the 5% then your data is significant.
This has been a guide to T.TEST in Excel. Here we discuss the T.TEST Formula in Excel and how to use T.TEST Function in Excel along with excel example and downloadable excel templates. You may also look at these useful functions in excel –