Answer:
The number of rooms he can wire with 3/4 of a roll of wire is 1/4.
What are proportions?
Proportion, in general, is referred to as a part, share, or number considered in comparative relation to a whole. Proportion definition says that when two ratios are equivalent, they are in proportion. It is an equation or statement used to depict that two ratios or fractions are equal.
Given that, an electrician needs 3 rolls of electrical wire to wire each room in a house.
Let the number of rooms he can wire with 3/4 of a roll of wire be x.
Now, the proportion is
3/1 = 3/4/x
3x=3/4
x=1/4