What is the difference between t test and chi square?

A t-test tests a null hypothesis about two means; most often, it tests the hypothesis that two means are equal, or that the difference between them is zero. A chi-square test tests a null hypothesis about the relationship between two variables.

What does it mean to reject the null hypothesis?

If there is less than a 5% chance of a result as extreme as the sample result if the null hypothesis were true, then the null hypothesis is rejected. When this happens, the result is said to be statistically significant .

What is p value formula?

The p-value is calculated using the sampling distribution of the test statistic under the null hypothesis, the sample data, and the type of test being done (lower-tailed test, upper-tailed test, or two-sided test). The p-value for: an upper-tailed test is specified by: p-value = P(TS ts | H 0 is true) = 1 – cdf(ts)

How do you select the null hypothesis for a chi square test?

The degrees of freedom for the chi-square are calculated using the following formula: df = (r-1)(c-1) where r is the number of rows and c is the number of columns. If the observed chi-square test statistic is greater than the critical value, the null hypothesis can be rejected.

What is chi square test in research methodology?

A chi-square test is a statistical test used to compare observed results with expected results. The purpose of this test is to determine if a difference between observed data and expected data is due to chance, or if it is due to a relationship between the variables you are studying.

What are the five steps of hypothesis testing in statistics?

Stating the research and null hypotheses and selecting (setting) alpha. Selecting the sampling distribution and specifying the test statistic. Computing the test statistic. Making a decision and interpreting the results.

How do you determine the level of significance in a hypothesis test?

In statistical tests, statistical significance is determined by citing an alpha level, or the probability of rejecting the null hypothesis when the null hypothesis is true. For this example, alpha, or significance level, is set to 0.05 (5%).

How do you interpret chi square results in SPSS?

Calculate and Interpret Chi Square in SPSS

  1. Click on Analyze -> Descriptive Statistics -> Crosstabs.
  2. Drag and drop (at least) one variable into the Row(s) box, and (at least) one into the Column(s) box.
  3. Click on Statistics, and select Chi-square.
  4. Press Continue, and then OK to do the chi square test.

What is chi square test used for?

The Chi-Square Test of Independence determines whether there is an association between categorical variables (i.e., whether the variables are independent or related). It is a nonparametric test. This test is also known as: Chi-Square Test of Association.

Is P value of 0.03 Significant?

So, you might get a p-value such as 0.03 (i.e., p = . 03). This means that there is a 3% chance of finding a difference as large as (or larger than) the one in your study given that the null hypothesis is true. 03, we would reject the null hypothesis and accept the alternative hypothesis.

How do you know when to reject the null hypothesis p-value?

If the p-value is less than 0.05, we reject the null hypothesis that there’s no difference between the means and conclude that a significant difference does exist. If the p-value is larger than 0.05, we cannot conclude that a significant difference exists.

How do you find the p value in a hypothesis test?

If your test statistic is positive, first find the probability that Z is greater than your test statistic (look up your test statistic on the Z-table, find its corresponding probability, and subtract it from one). Then double this result to get the p-value.

What are the steps involved in chi square test?

Compute the expected values. 4. Compute the chi-square statistic. Compare the computed chi-square statistic with the critical value of chi-square; reject the null hypothesis if the chi-square is equal to or larger than the critical value; accept the null hypothesis if the chi-square is less than the critical value.

What does P value signify?

A p-value is a measure of the probability that an observed difference could have occurred just by random chance. The lower the p-value, the greater the statistical significance of the observed difference. P-value can be used as an alternative to or in addition to pre-selected confidence levels for hypothesis testing.

What are the six steps of hypothesis testing?

  • Step 1: Specify the Null Hypothesis.
  • Step 2: Specify the Alternative Hypothesis.
  • Step 3: Set the Significance Level (a)
  • Step 4: Calculate the Test Statistic and Corresponding P-Value.
  • Step 5: Drawing a Conclusion.

Can P values be greater than 1?

P values should not be greater than 1. They will mean probabilities greater than 100 percent.

How do you read a hypothesis test?

A result is statistically significant when the p-value is less than alpha. This signifies a change was detected: that the default hypothesis can be rejected. If p-value > alpha: Fail to reject the null hypothesis (i.e. not significant result). If p-value <= alpha: Reject the null hypothesis (i.e. significant result).

How do you write the results of a chi square test?

This is the basic format for reporting a chi-square test result (where the color red means you substitute in the appropriate value from your study). X2 (degress of freedom, N = sample size) = chi-square statistic value, p = p value.