What is the term that refers to adding value to a product by making it more useful?

Asavings account that pays interest every 3 months is said to have a interest period

Who has summer school : ( because i do : (

Six years ago, an 80-kw diesel electric set cost $160,000. the cost index for this class of equipment six years ago was 187 and is now 194. the cost-capacity factor is 0.6. the plant engineering staff is considering a 120-kw unit of the same general design to power a small isolated plant. assume we want to add a precompressor, which (when isolated and estimated separately) currently costs $13291. determine the total cost of the 120-kw unit. (hint: skip $ and comma symbols)