Q:

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​

Accepted Solution

A:
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 = 82.4Customer Price Index 2000 = 172.2Price of a peanut butter jar 1980 = US$ 1.49Price of a peanut butter jar 2000 = xPrice increased at the same rate as the CPI2. 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 2000and now let's replace with the real values:x * 82.4 = 1.49 * 172.2x = (1.49 * 172.2)/82.4x = 256.578/82.4x = 3.1138x = 3.11 Rounding to two decimal placesThe 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 19803.11 - 1.49 = 1.62The 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.