In calculating the accounting rate of return using the straight-line method of depreciation,the annual average investment is calculated as (beginning book value + ending book value)/2.

Accounting Rate

Typically refers to the rate of return or interest rate used in financial calculations, such as net present value or internal rate of return.

Straight-Line Method

A method of calculating depreciation of an asset, which involves evenly spreading the cost of the asset over its useful life.

Annual Average Investment

The average amount invested over a certain period, typically calculated for evaluating investment performance.