Chi Square in AP Biology

What does the symbol χ² represent in the chi-squared test?

• Chi-squared

• Expected value

• Critical value

• Degrees of freedom

What is the purpose of the null hypothesis in the chi-squared test?

• To determine if observed data matches expected data

• To calculate the degrees of freedom

• To decide the number of experiments

• To set the critical values

How do you calculate degrees of freedom for a chi-squared test?

• Add one to the number of variables

• Subtract one from the number of outcomes

• Multiply the number of outcomes by two

• Divide the critical value by the number of outcomes

What does a critical value of 3.841 indicate in a chi-squared test?

• Only one degree of freedom is used

• There is a 95% confidence in the test results

• The null hypothesis is always rejected

• The observed values are exactly as expected

In the dice rolling example, why was the null hypothesis accepted?

• The observed values matched the expected values exactly

• All dice showed the same number

• There were more than six outcomes

• The chi-squared value was lower than the critical value