Return on operating assets = 25%

Operating asset turnover = 5 times
Operating assets = $20 million
Degree of operating leverage = 4 times

To calculate the Return on Operating Assets (ROOA), you need to multiply two factors: the Operating Asset Turnover and the Return on Sales (ROS). The formula for ROOA is:

ROOA = Operating Asset Turnover * ROS

1. Given the Operating Asset Turnover is 5 times:
Operating Asset Turnover = 5

2. We need to find the Return on Sales (ROS), which can be calculated by dividing the Earnings Before Interest and Taxes (EBIT) by Sales Revenue. However, since you haven't provided the EBIT or Sales Revenue, we can't calculate the exact ROS. Let's assume the ROS is 20% for this example.

ROS = 20%

3. Substitute the values into the formula to find the ROOA:

ROOA = Operating Asset Turnover * ROS
= 5 * 20%
= 100%

Therefore, the Return on Operating Assets is 100%.

Moving on to the Degree of Operating Leverage (DOL), it measures the sensitivity of operating income to changes in sales revenue. The formula for DOL is:

DOL = % change in Operating Income / % change in Sales Revenue

Given the Degree of Operating Leverage is 4 times:
DOL = 4

However, to calculate the % change in Operating Income and the % change in Sales Revenue, we need the initial and final values of both.

Without the specific values for those changes, we can only calculate the Degree of Operating Leverage as provided, which is 4 times.

Please provide more information if you need a more precise calculation.