Chapter 4

Question 1

What is a normal distribution?

Answer 1

-it is a symmetric bell shaped curve
-also known as a Gausian curve

Question 2

What is the formula for the normal distribution?

Answer 2

Question 3

Where is the IQR on normal distribution?

Answer 3

the middle 50%

Question 4

What is the formula for standardization on a standardized scale?

Answer 4

Question 5

How do you denote that Y is normal with mean u and SD sigma?

Answer 5

N(u,sigma)

Question 6

How do you denote that Z is normal with mean 0 and SD 1? What is Z called?

Answer 6

N(0,1)
-the standard normal

Question 7

What can you use to know whether data is distributed normally?

Answer 7

QQ-plots
-order the data y(1) < y(2) <…<y(100)
-y(i) is the approximate ith quantile
-y(70) is the 70th percentile
-then compare z score values
-plot data vs. expected values
-draw a line a non straight line implies the distribution is not normal

Question 8

What can you also use QQ-plots to test?

Answer 8

whether two data sets have the same distribution (even if the distribution is not normal