Displaying categorical and numerical data

Question 1

How do you graph a categorical variable?

Answer 1

Bar graphs

Question 2

What are two critical features of bar graphs?

Answer 2

1. The Y-axis always starts at 0

2. There are gaps between the bars

Question 3

How do you graph a numerical variable?

Answer 3

Histograms or cumulative frequency diagrams

Question 4

What features do histograms have?

Answer 4

1. Start at 0
2. No spaces between the bars
3. A value at a boundary goes into the next highest category
4. Space on either side to look prettier
5. States total sample size

Question 5

What are the 4 patterns seen in histograms?

Answer 5

1. Uniform
2. Normal
3. Asymmetric
4. Bimodal

Question 6

What is the interval width?

Answer 6

The width of the bands in histograms

Question 7

What is a percentile?

Answer 7

The percentage of observations less than or equal to a measurement. The remaining observations exceed that measurement

Question 8

What is a quartile?

Answer 8

Specific percentiles at 25%, 50%, 75%

Question 9

What is a quantile?

Answer 9

A cut-point that divides the range of a prob distribution

Question 10

What is a cumulative frequency diagram?

Answer 10

Is a graph that shows all quantities of a numerical value along an axis of percentiles

Question 11

What advantage do histograms have over cumulative frequency diagrams?

Answer 11

Show outliers better

Question 12

What advantage do cumulative frequency diagrams have over histograms?

Answer 12

Can sometimes show the overall spread of the data better