Final answer:
The average income in 1975 in 2018 dollars is approximately $64,152.42.
Step-by-step explanation:
To convert the average household income in 1975 to 2018 dollars, we need to adjust for inflation using the Consumer Price Index (CPI). The formula to do this is:
New Salary = (Old Salary) * ( New CPI / Old CPI)
Using the given information:
Old Salary = $13,800
Old CPI = 53.8
New CPI = 251.1
Plugging in the values, we can calculate the new salary as follows:
New Salary = ($13,800) * (251.1 / 53.8) = $64,152.42
Therefore, the average income in 1975 in 2018 dollars would be approximately $64,152.42.