Question

HELP ASAP! PLS!! The Water Department checks the city water supply on a regular basis for

Answer 1

Answer:

B. 95% confident the average concentration of PCBs in the water supply is between 2.9 ppb and 3.5 ppb

Step-by-step explanation:

You are given the total number of samples, the concentration of lead, and the standard deviation. The standard deviation represents how inaccurate the estimation of the concentration of lead in the drinking water. This means that there can only possibly be a 0.3 ppb error in the estimation. 3.2-0.3=2.9, and 3.2+0.3=3.5

Answer 2

Answer:

99.7% confident the average concentration of PCBs in the water supply is between 2.3 parts per billion and 4.1 parts per billion.

Step-by-step explanation:

Just took the question, this is the correct answer.