Question

In chi-square testing, the expected count is often calculated. What does it represent?

Group of answer choices

( )

The hypothetical counts that would occur if the null hypothesis were true.

( )

The observed counts from the representative data.

( )

The hypothetical counts that would occur if the alternative hypothesis were true.

( )

The true positive counts that occur.

Answer 1

Solution:

We are given that: In chi-square testing, the expected count is often calculated.

We have to explain what does it mean.

In chi-square testing, under the null hypothesis H0, we state that frequencies or counts occurs according to expected proportions or expected counts and under alternative hypothesis H1, we state statement against the null hypothesis. That is under alternative hypothesis H1, we state frequencies or counts does not occur according to expected proportions or expected counts.

For example: If we have to test if particular variable has uniform distribution, that is each category has an equal proportion or equal counts, then we find expected counts according to expected counts.

Rolling of a fair die.

H0: Die is fair , that is each face occur with equal counts.

Vs

H1: Die is not fair, that is counts of each face do not occurs with equal counts.

Thus if die is rolled 60 times ,then expected counts = 60 / 6 = 10

Thus each side of die has expected count = 10

Here  we calculated expected counts assuming null hypothesis is true.

Thus correct answer is:

The hypothetical counts that would occur if the null hypothesis were true.