In 2017, hart & sons, a small environmental-testing firm, performed 11 comma 400 radon tests for $ 260 each and 15 comma 000 lead tests for $ 210 each. because newer homes are being built with lead-free pipes, lead-testing volume is expected to decrease by 12% next year. however, awareness of radon-related health hazards is expected to result in a 5% increase in radon-test volume each year in the near future. jim hart feels that if he lowers his price for lead testing to $ 200 per test, he will have to face only a 4% decline in lead-test sales in 2018.