Chi-Squared test

Question 1

What is the chi-squared test?

Answer 1

it is used to see how closely the experimental (observed) results fit the expected outcome e.g. rolling the die

Question 2

When do you use the chi-squared test?

Answer 2

for a scenario where there is an expected outcome

Question 3

What is the equation for the chi-squared test?

Answer 3

χ2 = ∑(O– E)^2 /E

Question 4

What is the null hypothesis for the chi-squared test?

Answer 4

there is no significant difference between the observed and expected frequencies

Question 5

What is the degree of freedom for chi-squared test?

Answer 5

the number of possible outcomes - 1 e.g. coin toss 2 - 1 = 1 df

dice roll 6 - 1 = 5 DF

Question 6

What is the critical value in chi-squared test?

Answer 6

if the chi-squared value is greater than the critical value at P=0.05, you can reject the null hypothesis and less than 5% probability that the results occurred due to chance

Question 7

What might they give you in the exam?

Answer 7

a table to find the critical value and different probability ratings

Question 8

When you have to find the critical value through the table, what do you have to do first?

Answer 8

see how many degrees of freedom do we have for the experiment e.g. if we have two outcomes, we subtract them by 1 = 1df

Question 9

What do you compare the chi-squared value to?

Answer 9

to the critical value to see if it is greater or less than the critical value

Question 10

If the chi-squared value is greater than the critical value…

Answer 10

then you reject the null hypothesis but if less, then you accept it