# Dot Plots

A Dot Plot is a graphical display of data using dots.

### Example: Minutes To Eat Breakfast

A survey of "How long does it take you to eat breakfast?" has these results:

 Minutes: 0 1 2 3 4 5 6 7 8 9 10 11 12 People: 6 2 3 5 2 5 0 0 2 3 7 4 1

Which means that 6 people take 0 minutes to eat breakfast (they probably had no breakfast!), 2 people say they only spend 1 minute having breakfast, etc.

And here is the dot plot:

Another version of the dot plot has just one dot for each data point like this:

### Example: (continued)

This has the same data as above:

But notice that we need to have lines and numbers on the side so we can see what the dots mean.

## Grouping

Some people don't have access to electricity (they live in remote or poorly served areas). A survey of many countries had these results:

(% of population)
Algeria 99.4
Angola 37.8
Argentina 97.2
Bahrain 99.4
... ... etc

But hang on! How do we make a dot plot of that? There might be only one "59.6" and one "37.8", etc. Nearly all values will have just one dot.

The answer is to group the data (put it into "bins").

In this case let's try rounding every value to the nearest 10%:

(% of population,
nearest 10%)
Algeria 100
Angola 40
Argentina 100
Bahrain 100
... ... etc

Now we count how many of each 10% grouping and these are the results:

(% of population,
nearest 10%)
Number of
Countries
10   5
20   6
30   12
40   5
50   4
60   5
70   6
80   10
90   15
100   34