Math
posted by Edna on .
1. You have 3500 in savings for 9 months at a rate of 4.5%. How much will you have at the end of that time?
Ans. my book says: 3,618.13
I come up with: 118,125
2. Scale reads 1 inch = 24 inches for a house window. If window measures 1 3/4 inches, what is the actual length?
Ans. my book says: 3 ft 6 in
I come with 3.5
3. Scale reads 1 inch = 8 ft. If the width of the drawing is 2.25 inches and the length is 4 inches, what is the actual length of the deck's diagonal?
Ans. my book says: 37 ft.
I don't know how they came up with 37 ft.

1.
amount = 3500 + 3500(.045)(9/12)
= 3500 + 118.125
= 3618.13
Your answer is only the interest earned, you must add this to what you already have.
2.
you have 3.5 feet
= 3 feet + 1/2 foot  .5 = 1/2
= 3feet , 6 inches
3.
so the actual width of the deck is 18 ft and the length is 32 feet
by Pythagoras
H^2 = 18^2 + 32^2 = 1348
H = √1348 = 36.7 or rounded to 37 feet 
1.
Can't imagine how you got that answer. Even using 45%, I only get 99169!
However, 4.5% = .045 and that's an annual rate.
You want a monthly rate. Furthermore, you don't say whether that's simple interest or compounded monthly
Simple: 3500(1+.045/12*9) = 3618.13
so, I guess that's it.
2.
the scale indicates that the real dimensions are 24 times as large as the scale drawing.
1 3/4 = 7/4
7/4*24 = 42 inches = 3'6"
You are correct. Since a foot is 12 inches, the .5 foot is 6 inches.
3.5 feet = 3 feet 6 inches!
Keep track of the units, and don't lose track of conversions needed.
3.
This is just like #2.
1" = 8'
2.2" = 2.25(8') = 18'
4" = 4(8') = 32'
so, you have a rectangle that is 18x32.
Recall the Pythagorean Theorem, to see that the diagonal is
√(18^2+32^2) = √(324+1024) = √1348 = 36.7, or 37'