The TTEST Function in Excel is categorized as a Statistical Function. The function is frequently used to compare the probability of two samples having the same mean in their underlying populations.
Let’s say we’re doing financial research and want to know how much Europeans and Americans spend on food. We wouldn’t be able to keep track of every European and American’s purchasing patterns, so we’d take a sample of each group.
Therefore, in the scenario, the TTEST will help us to determine if the difference in food spending between the two groups is representative of a meaningful difference between Europeans and Americans in general or if it is merely a statistical difference.
In this tutorial, I’ll show you how to use Excel to do the TTEST function in Excel step by step. I will also show you how to choose the suitable type of TTEST, select the appropriate variables, and analyze the results.
Introduction to TTEST Function in Excel
▶ Function Objective
The TTEST function in Excel is used to determine the probability of a significant difference between two data sets, whether one or both are from the same population and have the same mean.
▶ Syntax
=TTEST(array1,array2,tails,type)
▶ Arguments Explanation
Argument  Required/Optional  Explanation 

array1  Required  The first data set 
array1  Required  The Second data set 
tails  Required  The number of distribution tails is defined.

type  Required 

▶ Return Parameter
Returns the TTEST probability. Use TTEST to see if two samples came from the same two underlying populations with the same mean.
Onetailed Test
A Onetailed test is a statistical test in which the critical region of distribution is onesided, meaning it is either greater than or less than a specific value, but not both.
You have two alternatives for the null and alternative hypotheses in a onetailed test, which correlates to where you position the critical region.
Null: The effect is less than or equal to zero.
Alternative: The effect is greater than zero.
Twotailed Test
Because you may analyze for both impacts., twotailed hypothesis tests are also known as nondirectional and twosided tests. Besides, your sample data are significantly unsuitable with the null hypothesis to invalidate it for the total population if a test statistic falls in a key area.
Null: The effect equals zero.
Alternative: The effect does not equal zero.
Paired TTEST
When comparing two variables for the same topic, we apply a paired TTEST. It’s a statistical method for determining if the mean difference between two sets of observations is zero.
TwoSample TTEST
The means of exactly two groups are compared in twosample TTEST—no more, no less! This test is usually used to see if the means of two populations are different.
For example, people who live in the USA have the same food and have a different mean score in price than those who have in Europe. This form of the test uses independent samples. Independent samples are used in this type of test. To put it another way, each group consists of a distinct set of people or stuff.
Using TTEST Function in Excel: 5 Suitable Methods
1. Apply OneTailed Test to TTEST Function in Excel
Assume we have the following information on household spending on food in Europe and the United States. The twosample TTEST is used because the samples are independent of one another.
Let’s imagine we want to see if the means of these two data sets in Europe are significantly different. For this, we can utilize the Onetailed TTEST. A onetailed test is a statistical test in which a distribution’s critical area is onesided, meaning it is either higher than or less than a particular value, but not both. The formula required for this case is,
Steps:
 Copy the formula text in the following table
 Paste it in cell C15 of a new Excel worksheet.
 Select 1 in the tails section for the Onetailed TTEST.
 Press Enter to see the results. You can adjust the column widths to see all the data if you need to.
2. Use Twotailed Test to TTEST Function in Excel
Let’s start with an explanation of what a Twotailed Test is.
The mean is equal to x, which is our null hypothesis. A twotailed test will determine whether or not the mean is substantially bigger than or less than x.
We will use a Twotailed TTEST in this example to determine the critical region of the distribution for both the higher and the lower than the specified mean value. Our formula is
=TTEST(B5:B12,C5:C12,2,1)
Steps:
 Copy the example data in the following table
 Paste it in cell C15 of a new Excel worksheet.
 Select 2 in the tails section for the Twotailed TTEST.
 Press Enter to see the results. You can adjust the column widths to see all the data if you need to.
3. Perform Paired Type to TTEST Function in Excel
When we want to compare the differences between two variables for the same subject, we utilize a paired TTEST.
Each subject or entity is measured twice in a paired sample TTEST, resulting in pairs of observations. Casecontrol studies and repeatedmeasures designs are common uses for the paired sample TTEST.
In the following example, we have obtained data from two separate locations on the same issue of food. In this case, the formula is,
=TTEST(B5:B12,C5:C12,1,1)
Steps:
 Copy the example data in the following table
 Paste it in cell C15 of a new Excel worksheet.
 Select 1 in the type section for Paired Type TTEST.
 press Enter to see the results. You can adjust the column widths to see all the data if you need to.
4. Apply Twosample Equal Variance TTEST Function in Excel
Generally, all TTESTs are based on the assumption that your data came from regularly distributed populations.
The traditional TTEST, on the other hand, assumes that both groups’ standard deviations/variances are equal.
The equal variance TTEST can be used when you are fairly certain that the variances are equal.
The required formula is,
=TTEST(B5:B12,C5:C12,1,2)
Steps:
 Firstly, Copy the example data in the following table
 Secondly, paste it in cell C15 of a new Excel worksheet.
 Then, select 2 in the type section for Twosample equal variance TTEST.
 Press Enter to see the results. You can adjust the column widths to see all the data if you need to.
5. Use TwoSample Unequal Variance TTEST Function in Excel
Conversely to equal variances, it’s significant to use the unequal variances option of the 2sample TTEST if you have unequal variances and unequal sample sizes.
Some analysts recommend using an FTEST to see if the variances are unequal. Excel also has the FTEST TwoSample for Variances option.
Other analysts advise applying a TTEST that assumes unequal variances all of the time. When the variances are equal, you lose a small amount of statistical power, but when the variances are not equal, you’ll be much better off. So the formula is,
=TTEST(B5:B12,C5:C12,1,2)
Steps:
 At first, copy the example data in the following table
 Next, paste it in cell C15 of a new Excel worksheet.
 Finally, Select 3 in the type section for the Twosample unequal variance TTEST.
 Finally, press Enter to see the results. You can adjust the column widths to see all the data if you need to.
✍ Things to Remember
✎ When the tails argument is not 1 or 2, or the given type argument is not one of the following numbers: 1,2 or 3, the #NUM! error occurs.
✎ #N/A! error occurs when the lengths of the two given arrays differ.
✎ Value error occurs when the given type of argument or the specified tails argument are both nonnumeric.
Download Practice Workbook
Download this practice workbook to exercise while you are reading this article.
Conclusion
To conclude, I hope this article has given you some useful information about how to apply the TTEST function in Excel. All these procedures should be learned and applied to your dataset. Look at the practice workbook and put these skills to the test. We’re motivated to keep making tutorials like this because of your valuable support.
If you have any questions – Feel free to ask us. Also, feel free to leave comments in the section below.
Stay with us & keep learning.