Descriptive Statistics

Question 1

What is the median of a set of data?

Answer 1

(n+1/2)

Question 2

What is the variance?

Answer 2

Combines all the values in a data set to produce a measure of the spread, the mean of the squared differences between each value and the mean value.

Question 3

What is the standard deviation?

Answer 3

The square root of the variance and has the same units of the data.

Question 4

What is the population variance?

Answer 4

n
@^2 = (E (x-u)^2)/ n
i=1

Question 5

What is the population standard deviation?

Answer 5

n
@ = sqr root( (E (x-u)^2)/ n)
i=1

Question 6

What happens to the mean when you add or subtract a constant value to all the numbers in a list?

Answer 6

The arithmetic mean increases or decreases by the constant.

Question 7

What happens to the standard deviation when you add or subtract a constant value to all the numbers in a list?

Answer 7

Remains the same.

Question 8

What happens to the mean when you multiply or divide a constant value to all the numbers in a list?

Answer 8

The mean is multiplied or divided by the constant.

Question 9

What happens to the standard deviation when you multiply or divide a constant value to all the numbers in a list?

Answer 9

The standard deviation is multiplied or divided by the constant.