Question is in description

Question

The price of a notebook was $3.50 yesterday. Today, the price rose to $3.75. Find the percentage increase. Round your answer to the nearest tenth of a percent. 

Answer 1

This is a great and quick formula for measuring percentage change:

 

% change = (new-old)/old

 

In this case, we want to find how much the price of the notebook changed. So, let P_old=3.5 and P_new = 3.75. The formula is then:

 

% change = (P_new-P_old)/P_old

 

% change = (3.75-3.5)/3.5

 

% change = (0.25)/3.5

 

% change = 0.071 = 7.1%

Answer 2

 

Percent of change = amount of change ÷ original amount

 

The amount of change is the difference between the 2 prices ... 3.75 - 3.50  = .25

 

    % change = .25/3.50

                    = .0714

                    = 7.14%