1143

Question 1

what are the 3 measures of dispersion

Answer 1

range
variance
standard deviation

Question 2

effects of outliers on range

Answer 2

strongly affected by outliers so limited usefulness

Question 3

what does IQR show

Answer 3

50% of the data around the mean

Question 4

how to identify outlier

Answer 4

IQR X 1.5 (+-) Q1/Q3

Question 5

variance definition

Answer 5

a measurement of how far each number in a data set is from the mean and thus from every other number in the set

Question 6

calculating variance steps

Answer 6

1- find the difference between each value and the mean
2- square these differences
3- add the differences together
4- divide by the number of data points (-1 if sample, if population divide by number of data points

Question 7

why do you square the deviations

Answer 7

• if you add all the deviaions you would get 0
• also to account for the negative numbers

Question 8

how to calculate standard deviation

Answer 8

square root the variance

Question 9

normal distribution definition

Answer 9

a probability distribution that is symmetric about the mean, showing that the data near the mean are more frequent in occurrence than data far from the mean

Question 10

standard deviation can only be used on normally distributed data, true or false

Answer 10

true

Question 11

what test determines whether data is normally distributed

Answer 11

Shapiro-Wilk test