Tests of a Difference in Means

Question 1

What are Problems with Collecting Data?

Answer 1

Undisclosed factors may change or affect results.

Question 2

What is the Assumption when Calculating Standard Error?

Answer 2

Population variances are equal.

Question 3

What are the Assumptions Made when Working with Dependent Samples?

Answer 3

Small sample size, population must be normally distributed for test to be valid.

Question 4

What are the Advantages of Matched t-Tests?

Answer 4

By differencing the data, we remove variance as factors are unrelated. Fixed effects.
As a result of the lower sample variance, SE is lower.
P(Type 2 error) is reduced, so Power is increased.