Answer:
Step-by-step explanation:
First you will subtract right to left and then what ur left with is the sum.
Solve the absolute value equation.
First subtract 5 from both sides.
|x|+5=18
|x|=13
If the absolute value of x is 13 that x equals 13 and -13. Absolute value means distance from 0.
x=13,-13
Start with the original expression.
Use the Distributive Property — multiply 
by both 
and 
.
Combine the like terms — add up all the constants.
Reorder the terms.
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
