Data presentation and interpretation

Question 1

How to calculate outlier

Answer 1

Greater than: Q3+ k(Q3-Q1)
Less than: Q1- k(Q3-Q1)

Question 2

How to calculate IQR

Answer 2

upper quartile - lower quartile

Question 3

Would you use the mean and SD or the median and IQR to describe the data, if outliers are present

Answer 3

Due to outliers in the data, the mediam and IQR should be used as outliers affect the mean and SD

Question 4

Why use class midpoints to calculate an estimate of a mean from a grouped frequency table

Answer 4

Assumes that the values are uniformly distributed within the classes

Question 5

How does outliers affect the mean

Answer 5

Outliers can pull the mean towards their extreme values