Question

From 1980 to 2000 the consumer price index increased from 82.4 to 172.2. If a jar of peanut butter cost $1.49 in 1980 and the price of peanut butter increased at the same rate as the cpi from 1980 to 2000 by approximately how much did the price of a jar of peanut butter increase from 1980 to 2000? A. .82 B. $1.72 C.1.62 or D. $3.11​

Answer 1

Answer:

The price of the peanut butter jar in 2000 is US$ 3.11 and it increased US$ 1.62 from 1980 to 2000. The correct answer is C. 1.62.

Step-by-step explanation:

1. Let's review all the information provided for solving this question:

Customer Price Index 1980 = 82.4

Customer Price Index 2000 = 172.2

Price of a peanut butter jar 1980 = US$ 1.49

Price of a peanut butter jar 2000 = x

Price increased at the same rate as the CPI

2. Using Rule of Three we will find the  price of the peanut butter jar in 2000:

x * CPI 1980 = Price of the peanut butter jar in 1980 * CPI 2000

and now let's replace with the real values:

x * 82.4 = 1.49 * 172.2

x = (1.49 * 172.2)/82.4

x = 256.578/82.4

x = 3.1138

x = 3.11 Rounding to two decimal places

The price of the peanut butter jar in 2000 is US$ 3.11.

Now let's find how much it increased from 1980 to 2000:

Price in 2000 - Price in 1980

3.11 - 1.49 = 1.62

The price of the peanut butter jar in 2000 is US$ 3.11 and it increased US$ 1.62 from 1980 to 2000. The correct answer is C. 1.62.