For this case what we have to take into account is the following variable:
x = represent the unknown number
We now write the following inequality:
"four times the sum of number and 15 is at least 20"
4 (x + 15)> = 20
We clear the value of x:
(x + 15)> = 20/4
(x + 15)> = 5
x> = 5 - 15
x> = - 10
The solution set is:
[-10, inf)
Answer:
all possible values for X are:
[-10, inf)
Answer: B. x is all real numbers.
Step-by-step explanation: The domain of a graph is how far the x value can go left or right. Because this is a horizontal line, the domain or x could be any value.
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
