Chapter 3: Representations of Data

Question 1

What point is used for plotting a cumulative frequency diagram?

Answer 1

Plot each point using the upper class boundary for x and the cumulative frequency for y.

Question 2

How is the area of a bar in a histogram determined?

Answer 2

area of bar = k x frequency

Question 3

How is the frequency density (the height) of each bar calculated when k = 1?

Answer 3

If k = 1, then
frequency density = frequency / class width

Question 4

How is a frequency polygon formed?

Answer 4

Joining the middle of the top of each bar in a histogram forms a frequency polygon.

Question 5

How is data compared?

Answer 5

You can compare data using the mean and standard deviation or using the median and interquartile range. If the data set contains extreme values, then the median and interquartile range are more appropriate statistics to use.