Final answer:
The adjusted monthly benefit of a Social Security recipient can be calculated using the formula I(x) = (1 + COLA) * x. If Harrington's current monthly benefit is $520 and the consumer prices increased by 5.4%, his adjusted monthly benefit would be $547.68.
Step-by-step explanation:
(a) The adjusted monthly benefit of a Social Security recipient as a function of his or her current monthly benefit, can be expressed by:
I(x) = (1 + COLA) * x
Where x is the current monthly benefit and COLA is the cost-of-living adjustment as a decimal.
(b) If Harrington's current monthly Social Security benefit is $520 and the consumer prices have increased by 5.4%, his adjusted monthly benefit can be calculated as follows:
I(x) = (1 + 0.054) * 520
I(x) = $547.68