9514 1404 393
Answer:
- $0.04 per cubic foot
- c(w) = 0.04w +80
- 3400 cubic feet
Step-by-step explanation:
(a, b) We are given two pairs of values:
(w, c) = (1900, 156) and (2600, 184)
so we can write the equation of the relationship using the 2-point form of the equation of a line.
y = (y2 -y1)/(x2 -x1)(x -x1) +y1
c = (184 -156)/(2600 -1900)(w -1900) +156 . . . . . substitute given points
c = 28/700(w -1900) +156
c(w) = 0.04w +80
The charge per cubic foot is $0.04.
__
(c) For a bill of $216, the amount of water used is ...
216 = 0.04w +80
136 = 0.04w
3400 = w
Use of 3400 cubic feet of water would lead to a bill of $216.
87 years I think…. If a score is 20 years and four scores have passed you do 4x20 = 80. 80 plus the seven 80+7 = 87
First, to find out the number of students who scored below Amanda, we must find the z-score value of Amanda's score using the formula below.

where Z is the z-score, Χ is the expected average value, μ is the mean of Χ, and δ is the standard deviation. Thus, we have


Thus, using the z-table, we have P(Z<0.90) = 0.8159. Since we have wanted to find the number of students who scored below Amanda, then from the whole, we have (1 - 0.8159) = 0.1841. That means, out of 1000 students, 0.1841 of them scored below Amanda. Thus, we have (0.184)(1000) = 184.
Answer: 184 students
The logarithm and the exponential are inverse function:

So, we have

And so in particular we have
