# TTEST

The `TTEST` formula is a statistical formula used to determine the probability of two sample means being equal. It is commonly used in hypothesis testing to determine if there is a significant difference between two sets of data. The formula returns the probability value associated with a t-test, which can be used to determine if the null hypothesis should be rejected or not.

## Usage

Use the `TTEST` formula with the syntax shown below, it has 3 required parameters and 1 optional parameter:

Parameters:
1. range1 (required):
The first range of data for the t-test.
2. range2 (required):
The second range of data for the t-test.
3. tails (required):
The number of tails for the distribution. Should be either 1 (one-tailed) or 2 (two-tailed).
4. type (optional):
The type of t-test to perform. Should be either 1 (paired) or 2 (unpaired). Defaults to 2 if not specified.

## Examples

Here are a few example use cases that explain how to use the `TTEST` formula in Google Sheets.

### Comparing two sets of data

You can use `TTEST` to determine if there is a significant difference between two sets of data. For example, you might use it to compare the effectiveness of two different marketing campaigns.

### Analyzing survey results

If you have two sets of survey results, you can use `TTEST` to see if there is a significant difference between the two groups. This can help you draw conclusions about the effectiveness of your survey questions.

### Determining statistical significance

You can use `TTEST` to determine if the difference between two groups is statistically significant. This can help you draw more accurate conclusions from your data.

## Common Mistakes

`TTEST` not working? Here are some common mistakes people make when using the `TTEST` Google Sheets Formula:

### Using non-numerical data

The `TTEST` formula can only be used with numerical data. If non-numerical data is used, the formula will return an error. Make sure that the ranges being used in the formula only contain numerical data.

### Using ranges with different sizes

The `TTEST` formula requires that the ranges being compared have the same number of values. If ranges with different sizes are used, the formula will return an error. Make sure that the ranges being used in the formula have the same number of values.

### Not specifying the number of tails

The `TTEST` formula requires that the number of tails is specified in the formula. If this parameter is not included, the formula will return an error. Make sure that the number of tails is specified in the formula.

The following functions are similar to `TTEST` or are often used with it in a formula:

• `AVERAGE`

The AVERAGE function calculates the average (arithmetic mean) of the values passed to it. It is commonly used to find the average of a range of cells containing numerical data.

• `STDEV`

The `STDEV` function calculates the standard deviation of a set of numbers. It measures the amount of variation or dispersion of a set of values from the average (mean) value. It is commonly used in statistics to determine the spread of a data set. The values can be supplied as individual cells, ranges, or constants.

• `CORREL`

The `CORREL` formula returns the correlation coefficient between two sets of data. This coefficient represents the strength of the linear relationship between the two sets of data, with values ranging from -1 (perfect negative correlation) to 1 (perfect positive correlation).

• `ZTEST`

The ZTEST function in Google Sheets returns the one-tailed probability-value of a z-test. It is used to determine whether a sample mean is significantly different from a hypothesized value, assuming a known population standard deviation. This function is typically used in hypothesis testing and statistical analysis.

You can learn more about the `TTEST` Google Sheets function on Google Support.