HELP ASAP! PLS!! The Water Department checks the city water supply on a regular basis for
contaminants such as lead. The Water Department takes 200 samples and
estimates that the concentration of lead in your drinking water is 3.2 ppb
(parts per billion), with a standard deviation of 0.3 ppb.
Assuming the samples were random and unbiased, how much confidence
can you have in this data?
O
A. 99.7% confident the average concentration of PCBs in the water
supply is between 2.3 ppb and 4.1 ppb.
O
B. 95% confident the average concentration of PCBs in the water
supply is between 2.9 ppb and 3.5 ppb.
O
C. 97% confident the average concentration of PCBs in the water
supply is between 2.6 ppb and 3.8 ppb.
O
D. 68% confident the average concentration of PCBs in the water
supply is between 3.1 ppb and 3.3 ppb.

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.

idk bring the function back   im not smart

step-by-step explanation:

pentagon

step-by-step explanation:

the coordinates   a(5, -2), b(3,-1),c(-4,-4) d(-3,8) and e(-1,4) forms the vertices of the polygon when they are connected in order.

in order to classify that which polygon is it with the given coordinates, first count the number of vertices and then count the number of sides it can make with these vertices.

since, the given coordinates have five vertices, therefore, it will make five sides. moreover, pentagon is regular in nature therefore it will be convex.

now, a polygon with five sides is known as pentagon, therefore, the given polygon is the pentagon.