Module 7: Assumptions

Question 1

What are the two ways to test one sample mean?

Answer 1

if we know both the mean* and sd, we use the z-test

if we know only the mean and not sd, we use the t-test

population*

Question 2

What are the 3 assumptions of using z-tests and t-tests?

Answer 2

These assumptions apply to both z-test and t-test

1. Data comes from a random sample
2. Dependent variable measured at interval / ratio level
3. Data is approximately normally distributed

Question 3

Assumptions: 1. Data comes from a random sample

What does the first assumption mean?

Answer 3

Random Sampling =
randomly selecting a sample from a population

Random Assignment =
radnomly assigning individuals from the sample into groups

Question 4

Assumptions: 3. Data is approximately normally distributed

What can we use to ensure we have a normal distribution?

Answer 4

Question 5

Example of Normally distributed Graphs:

Answer 5

Question 6

Assumptions: 3. Data is approximately normally distributed

Example pf Q-Q Graph. Label

Answer 6

Question 7

Assumptions: 3. Data is approximately normally distributed

Which one should we use?

Answer 7

All of them, each one describes a different characteristic of normality (each piece of information is relevant)