Using Mean and Standard deviation

Question 1

When is a data value considered unusual?

Answer 1

When it is more than 2 standard deviations from the mean

Question 2

How to calculate whether a data is unusual?

Answer 2

1) Calculate the mean of the data set
2) Find the standard deviation
3) Both subtract and add 2 stand deviations from the mean
4) ((sample mean -/+ 2(standard deviation))=The lowest or highest number that would not be considered unusual)
5) Anything past the lowest and highest answer would be considered unusual

Question 3

Empirical or Standard deviation rule (68-95-99.7% rule)

Answer 3

one standard deviation needs 68% of data sets to be included, two SD needs 95%, three SD needs 99.7%

Question 4

what does a z-score do?

Answer 4

It measures the distance of a data point from the mean of the data in standard deviation form

Question 5

z-score formula

Answer 5

z=(x-(x with a line above it))/s

Question 6

x with a line above it

Answer 6

sample average

Question 7

lower case s

Answer 7

standard deviation for a sample

Question 8

omega symbol

Answer 8

standard deviation for a population