Lecture #7 (Comparing Variances)

Question 1

What is the F-test used for?

Answer 1

The F-test is used for testing if the two variances are statistically different

Question 2

How do you calculate F-stat?

Answer 2

F-stat = (𝑆²₁ / 𝑆²₂)

Question 3

If F-stat is greater than F-crit, what do we accept?

Answer 3

H₁

Question 4

How do you perform the F-test?

Answer 4

Calculate descriptive statistics, perform T/Z-test for the mean and use the F-test formula to compare variances

Question 5

In the F-test, what can you conclude if the mean and variances are proven similar?

Answer 5

We accept H0

Question 6

In the F-test, what can you conclude if the variance is different but the mean is the same?

Answer 6

We accept H0

Question 7

What is ANOVA?

Answer 7

analysis of statistically significant variation where there are more than two samples

Question 8

What steps do you take in ANOVA?

Answer 8

1) Organize and visualize data
2) Calculate individual and total counts of sums, n and means
3) Calculate the total sum of squares (SSₜ)
4) Calculate the individual sum of squares (SS𝓌)
5) Calculate between the two groups (SSb)
6) Calculate degrees of freedom (nT-1)+(nE-1)