Answer:
1. Using a method similar to that used to calculate the consumer price index, the percentage change in the overall price level is;
Value of market basket of the good in 2020
= (50 * 2) + (5 * 6)
= $130
Value of market basket of the good in 2021
= (70 * 2) + (6 * 6)
= $176
CPI in 2020
= 130/ 130 * 100
= 100
CPI in 2021
= 176 / 130 * 100
= 135.38
Percentage change
= (135.38 - 100)/100
= 35.38%.
2. Using a method similar to that used to calculate the GDP deflator, the percentage change of the overall price level is ;
Nominal GDP in 2020 = (50 * 20) + (5 * 60) = $1,300
Nominal GDP in 2021 = (70 * 21) + (6 * 80) = $1,950
Real GDP using 2020 prices
Real GDP in 2020 = (50 * 20) + (5 * 60) = $1,300
Real GDP in 2021 = (50 * 21) + (5 * 80) = $1,450
GDP deflator in 2020 = (Nominal GDP in 2020 / Real GDP in 2020) * 100 = (1,300 / 1,300) * 100 = 100
GDP deflator in 2021 = (Nominal GDP in 2021 / Real GDP in 2021) * 100 = (1,950 / 1,450) * 100 = 134.48
Percentage Change = [(134.48 - 100) / 100] * 100
= 34.48%