Lecture 3 - Statistical Inference

Question 1

When are the mean, mode, and median the same?

Answer 1

normal distributions (bell curve)

Question 2

What does sigma represent?

Answer 2

population variance

Question 3

What does mu represent?

Answer 3

population mean

Question 4

What are representative or typical values ?

Answer 4

They fall within 1 SD of the mean.

68.36% of our population

Question 5

What are unrepresentative or atypical values ?

Answer 5

They fall outside of 3 SD’s of the mean (which includes 99.74% of our population).

Question 6

What are somewhat representative values ?

Answer 6

values that fall within 2 SD’s of the mean (this includes 95.44% of population)

Question 7

By convention, “unrepresentative” is generally accepted as __% of a set of data

Answer 7

5

Question 8

The middle ___% is representative and somewhat representative defined by +/- 1.96SD

Answer 8

95