Critical Value Calculator

How to Use the Critical Value Calculator

This guide will walk you through the steps of using the Critical Value Calculator to compute the critical value, p-value, and significance level for various statistical tests. This tool is particularly useful for hypothesis testing in statistics.

Step 1: Select the Confidence Level

Begin by selecting the appropriate Confidence Level for your test. This represents how confident you want to be in your results. Common options include:

• 90%
• 95%
• 98%
• 99%

Select the option that matches the confidence level you require for your hypothesis test.

Step 2: Enter Degrees of Freedom

In the Degrees of Freedom field, enter the number of degrees of freedom for your statistical test. The degrees of freedom should be a whole number between 1 and 1000. This value is related to your sample size and the type of test you are performing.

Step 3: Choose the Test Type

Next, select your desired Test Type. Your choices are:

• Two-tailed: Use this option if your hypothesis test looks for any significant difference from the null hypothesis in both directions.
• Left-tailed: Use this option if your hypothesis test is searching for a significant decrease.
• Right-tailed: Use this option if your hypothesis test is looking for a significant increase.

Step 4: Calculate Results

After entering all the necessary information, the calculator will automatically compute the following:

• Critical Value (t): This is the threshold value that the test statistic must exceed to reject the null hypothesis.
• P-Value: This indicates the probability of observing a test statistic as extreme as the one computed, under the null hypothesis.
• Significance Level (α): This is derived from the confidence level and represents the probability of rejecting the null hypothesis when it is true.

Review these results in the context of your statistical test to draw conclusions and determine if your results are statistically significant.