Question

for making a scatter plot of this data set, which would be the best scale and interval for the axis that represents the amount of fluoride?

water (l)	2	1	1.5	4	3	1	5
fluoride (mg)	1.1	0.8	1.2	3.2	1.6	0.2	3.6

o 1 to 4 with intervals of 1
o 2 to 5 with intervals of 0.1
o 0 to 4 with intervals of 0.2
o 0 to 4 with intervals of 2

Explanation:

Step1: Find the minimum and maximum values

The minimum value of fluoride is $0.2$ mg and the maximum is $3.6$ mg.

Step2: Analyze each option

• Option 1: 1 to 4 with intervals of 1. The minimum value $0.2$ is not included, so it's not suitable.
• Option 2: 2 to 5 with intervals of 0.5. The minimum value $0.2$ is not included, so it's not suitable.
• Option 3: 0 to 4 with intervals of 0.2. It includes all values from the data - set ($0.2$ - $3.6$) and has a reasonable interval for plotting.
• Option 4: 0 to 4 with intervals of 2. The interval is too large, which will not show the data points accurately.

Answer:

0 to 4 with intervals of 0.2