A coworker comes to you with the following problem.

"I provided my boss a projection of factory overhead using the high-low method. He was unhappy with the results and told me to do more work and not return until I had a lower cost estimate. My initial analysis was based on data points for the last 24 months. By dropping the three highest data points, I was able to get a lower cost."

Was what your coworker did unethical? Explain.