The scale factor of the Reba's drawing is 9/84, 3/28
Explanation:
The scale factor is the ratio between the two corresponding sides of the figure. The point worth noting in computing the scale factor is that both sides must have similar units of dimension while using for comparison purpose.
Given the scale used by Reba is 9 inches to 7 feet
Since both the units are different, we have the option to either convert inches to feet or vice versa
We proceed with converting feet to inches
We know that 1 foot equals to 12 inches. Hence 7 feet would equal 84 inches.
Now scale factor= first dimension/ corresponding dimension
Scale factor= 9/84 which can be reduced to 3/28