Answer:
Petroleum = 15.32%
Drugs = 12.9%
Chemicals = 2.5%
Motor Vehicles = -56.5% (Negative)
Electrical = -18.8% (Negative)
Food = 3.7%
Step-by-step explanation
Here we have to use the formula to find the percentage of increase.
Percentage of increase = Increased amount / original amount * 100
Let's find the percentage of increase of each firm from 1966 and 1974
Petroleum = ((12.8 - 11.1) ÷ 11.1)) *100 = (1.7 ÷ 11.1)*100 = 15.32%
Drugs = ((12.2 - 10.8) ÷ 10.8)) *100 = (1.4 ÷ 10.8)*100 = 12.9%
Chemicals = ((8.2 - 8) ÷ 8)*100 = (0.2 ÷ 8)*100 = 2.5%
Motor Vehicles = ((2.7 - 6.2)÷6.2)*100 = (-3.5÷6.2)*100 = -56.5% (Negative)
Electrical = ((3.9 - 4.8)÷4.8)*100 = (-0.9÷4.8)*100 = -18.8% (Negative)
Food = ((2.8-2.7)÷2.7))*100 = (0.1 ÷2.7)*100 = 3.7%
Hope you will understand the concept.
Thank you.