Summary of Wednesday, Dec. 10 and Answer Key

Hello All!
Not too much time for pleasantries today because there is a lot on my plate and probably yours too. So, without further hesitation, I'll give you the best answers that I can from the test 3 review yesterday considering there are no graphics.
Page 1, #1 a) 82%
b) 2% of 200 = 4 batteries will die before 27 hours
#2 a) 0.6 mi.
b) 567,000 cm
c) 46.8 sq. ft.
d) 1.71 m
e) 125.59 in.
Page 2, #1 a) When graphing the line y = 4x + 7, it should start at the
point (0,7) and rise to the point (20,87). When graphing y = 1.5x + 8
the point (0,8) is the first and most obvious point, and the second
would be (20,38). If you plotted them accurately the two lines would
look like they are almost starting together and fanning out from there.
(On the test I'll give you a good idea of what numbers to choose
for your horizontal axis.)
b) The lines C = .25d + 15 and C = .3d + 10 have the same
general form -- that is, y = kx + F, where k is the slope and F is the
fixed point (also known as the intercept). It was pointed out on the
handout that you should use values from 0 to 100 for "d". In this
example "d" is the dependent variable and is to be plotted on the
horizontal axis. The first lines starts at (0,15) and goes upward to
(100,40). The second line starts at (0,10) and goes upward until it
meets the other line at (100,40).
#2 a) I asked for four points but you should have included at least
the points (0, 3.50) and (40, 47.50) since I stipulated that in the
question. The other two points will vary with each person but the line
itself won't vary when it is graphed.
b) C = 1.10d + 3.50 (where C = cost in dollars and d = km)
c) If your line goes through the points given in (a) part of the
question accurately then it is correct. Show me your graph
on Monday if you need to be sure.
d) When comparing two deals, first evaluate each one.
Company A would be 1.10(13) + 3.50 = $17.80
Company B would be 1.15(13) + 3.25 = $18.20
Note: You could have tried to graph the second company
but in this case a $0.40 difference would be hardly noticable.
Calculating when it is that close, would be required.
Page 3, #3 a) Area = wall - window - door (change all units into feet)
Area = 112 - 8.75 - 15
Area = 88.25 sq. ft. (or 88 1/4 sq ft)
That is equivalent to approx. 8.198 sq. m.
b) Each door is 63 sq ft and there are four of them for a total
of 252 sq. ft. The total wall is 14.25 x 68 = 969 sq. ft.
Area to be painted is the difference, 969 - 252 = 717 sq. ft.
Each large can of paint covers 360 sq. ft.
3 cans are needed for a total cost of 3 x 47.99 = $143.97
If calculating taxes the final price would be $161.25.
#4 a) kA = 1
b) kB = 2
c) kC = -4
d) kD = undefined
e) kE = 0