Answer:
a. Use the regression equation
Explanation:
Given
See attachment for missing part of question
Required
What can be used to predict diameter, given family income
We can see (by observation) that the data on the table can only be represented on a scattered plot, and scattered plot uses regression equation for data prediction.
i.e.
--- equation of line of best fit
In this case;
When the x value (income) is known, we can simply plug in the value in the above equation to get the y value (diameter)