Test Statistic Calculator

Try the test statistic calculator to estimate the t-value of a given dataset within seconds by providing a couple of simple inputs.

This calculator takes sample mean, population mean, standard deviation, and sample size into account to calculate t statistics precisely.

What Is T Statistic And Student’s T-Test?

A particular statistical calculation that figures out the relationship between the sample and its population is known as the test statistics.

It’s a score that is used in the hypothesis test and informs about how likely the results are under the assumption that the null hypothesis is true.

Moreover, a student’s t-test is used to evaluate hypotheses about the population mean. It tells whether you should support or reject the null hypotheses.

Test Statistic Formula?

The test statistic formula depends on the population standard deviation (σ) whether it’s known or unknown. Let’s take a look at the following general test statistic equations:

For UnKnown Standard Deviation:

t = $\frac{\overline{x} – μ_0}{\frac{s}{\sqrt{n}}}$

For Known Standard Deviation:

t = $\frac{\overline{x} – μ_0}{\frac{σ}{\sqrt{n}}}$

Where

$ \overline{x} $ indicates the sample mean
μ shows the population mean
n is the representative of the sample size
s is the standard deviation

Use the above mentioned formula sourced from Wikipedia to compute your test statistic.

How To Calculate Test Statistic?

There are different standard cases that you must know to perform test statistics. Below we have four standard cases for which t value formulas differ.

One Population Mean:

Calculating one population mean, if the variable is numerical and one population or one group is being studied.

For instance, you believe that the students of O level spend $20 a day, here the variable is numerical and the population is the students of O level. In this case, it’s good to use one population mean.

Test Statistic for One Population Mean = $\frac{\overline{x} – μ_0}{\frac{σ}{\sqrt{n}}}$

Comparing Two Means:

This test is good when the variable is numerical and you have to compare two populations or groups. For this, you must choose two separate random samples from each population.

Test Statistic Comparing Two Means = $\frac{\overline{x} – \overline{y}}{\sqrt{\frac{σ^2_x}{n_1} + \frac{σ^2_y}{n_2}}}$

Single Population Proportion:

Perform this calculation, when the variable is categorical such as genders, workers/ unemployed and one population has to be considered.

Test Statistic for a Single Population Proportion = $\frac{\stackrel{\text{^}}{p} – \ p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}}$

Two Population Proportions:

Use it when the variable is categorical, and you have to consider the proportion of two individuals having specific characteristics of two different categories such as male/female.

Test Statistic for Two Population Proportions = $ \frac{\stackrel{\text{^}}{p_1}-\stackrel{\text{^}}{p_2}}{\sqrt{\stackrel{\text{^}}{p}(1-\stackrel{\text{^}}{p})(\frac{1}{n_1} + \frac{1}{n_2})}} $

Practical Example:

Let us make a supposition for a cricket series in which Jack has an average score of 66 or consecutive 16 matches. Now as you better know an average batting average for a player is 40 (maximum). Keeping in view the deviation in scoring that is 4 in the case, what are the performance stats of Jack? Now how to find the test statistics?

Solution:

Data Given:

$\overline{x}=66$

$n=16$

$μ=40$

$σ=4$

Calculations:

$\text{Test Statistic}=\frac{\overline{x} – μ_0}{\frac{σ}{\sqrt{n}}}$

$\text{Test Statistic}=\frac{66 – 40}{\frac{4}{\sqrt{16}}}$

$\text{Test Statistic}=\frac{26}{\frac{4}{4}}$

$\text{Test Statistic}=\frac{26}{1}$

$\text{Test Statistic}=26$

Now as the computed value is 26, find a Standardized test statistic calculator to verify it. With it, you will have the correct results in fractions of seconds.

FAQ’s:

Who Is The Father of Student’s T-Distribution?

Gosset was a talented statistician who proposed the theory of student’s t-distribution in the year 1908.

Is The Test Statistic The Z Value?

A z score is a value that shows a standard deviation above or below the mean. Meanwhile, it represents the relationship of value with the mean of a group.