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Which is better chi square or t-test?

T-test allows you to differentiate between the two groups. While the Chi-square test also helps you to find the relationship between two variables but has no direction and size of the relationship. difference between the two groups while in the Chi-square test there is no relationship between two variables.

What is chi-square value?

The chi-squared statistic is a single number that tells you how much difference exists between your observed counts and the counts you would expect if there were no relationship at all in the population. A low value for chi-square means there is a high correlation between your two sets of data.

What is chi-square and its properties?

Properties of the Chi-Square Is the ratio of two non-negative values, therefore must be non-negative itself. Chi-square is non-symmetric. There are many different chi-square distributions, one for each degree of freedom. The degrees of freedom when working with a single population variance is n-1.

Is Chi Square always skewed right?

The chi-square distribution curve is skewed to the right, and its shape depends on the degrees of freedom df. For df>90, the curve approximates the normal distribution. Test statistics based on the chi-square distribution are always greater than or equal to zero.

Is Chi square a parameter?

The chi-square distribution has one parameter: a positive integer k that specifies the number of degrees of freedom (the number of random variables being summed, Zi s).

Why chi square test is a nonparametric test?

A large sample size requires probability sampling (random), hence Chi Square is not suitable for determining if sample is well represented in the population (parametric). This is why Chi Square behave well as a non-parametric technique.

What is chi-square distribution give its limitations?

First, chi-square is highly sensitive to sample size. As sample size increases, absolute differences become a smaller and smaller proportion of the expected value. Generally when the expected frequency in a cell of a table is less than 5, chi-square can lead to erroneous conclusions. …

What shape is a chi-square distribution?

skewed

What is the minimum sample size for chi square test?

5

What is chi-square test for proportions?

The chi-squared test works by calculating the frequencies we would expect to see in the cells if there were absolutely no association. It works like this. For the HIV test data, the proportion who accepted the test is 134/788.

What is effect size in chi-square tests?

There are three different measures of effect size for chi-squared test, Phi (φ), Cramer’s V (V), and odds ratio (OR). V = χ 2 n · d f , where n is total number of observation, and df is degrees of freedom calculated by (r – 1) * (c – 1). Here, r and c are the numbers of rows and columns of the contingency table.

How do you calculate the effect size?

Effect size equations. To calculate the standardized mean difference between two groups, subtract the mean of one group from the other (M1 – M2) and divide the result by the standard deviation (SD) of the population from which the groups were sampled.