A Group of Concerned Citizens Was Worried That Their Local

Multiple Choice

A group of concerned citizens was worried that their local water supply might be contaminated with naturally occurring arsenic. They decided to purchase a home arsenic monitoring kit and tested well water in their local area. After analyzing the data (shown below) , the citizens wrote a letter to the editor of a local newspaper arguing that their data proved that the water supply is contaminated. They demanded immediate government action to address the problem. The local water board again tested the wells using their official water testing instruments and found average concentrations of 8.1 +/- 0.2 micrograms per liter. Assume the water board's reported measurements are the accepted value. The maximum permitted level of arsenic in water supplies is 10 micro-grams per liter.

-The citizens decide to retest the water and obtain 11.1 +/-0.2 micrograms per liter and again argue for action. Which statement below best describes the new data reported by the concerned citizens?

A) Their data are accurate, but not precise.
B) Their data are precise, but not accurate.
C) Their data are not accurate or precise.
D) Their data are accurate and precise.