posted by Celina on .
I really need help with my math homework today, because I am totally confused! Please give me the answer, but also walk me through it, too, so I can fully understand it, because just the answer won't really help.
#1: A math teacher wants to curve a set of grades. *Just a note, I don't even understand what curve means* She wants to create a formula to turn an old grade, s, into a new grade, t, where t = As + B for some constants A and B. She wants this formula to give a 100 to a student who originally scored 100, and a score of 81 to a student who originally scored 62.
a. How can we view the pairs of original and new scores as points on a line?
b. Use your answer to part a. to determine A and B in the formula.
c. What grade should a student who originally scored 74 receive?
I will post more questions in a little bit. Thank you so much, any help is appreciated, even if you can only answer part of it.
well, if an original 100 gives a 100
and if a 62 is turned into and 81 (magic wand).
You have two equations, two unknowns.
First, subtract the second equation from the first.
100-81=A(100-62) And you solve for A.
Then, put that A into either equation and solve for B.
Thanks for replying so fast!
Once you got to "subtract the second equation," I got a little confused.
So basically its, 100-81=A(100-63), like you said. Does the B stay put?
And what do you mean by "solve for A" and "put A into either equation?"
Thanks so much!
When you subtract the second equation fromthe first, you have B-B which is zero, so B disappears.
Solving for A?
Now put that into any equation..
100=100(19/37) + B
and you have A and B
check my arithmetic
Oh, I see... when I got 19/37 when I solved, I thought I was incorrect.
One last thing-- why did you write
B= 100(1-19/37)=100(18/37)? Why did you take away 1?
100=100(19/37) + B
subtract 100(19/37) from each side.
I hate to ask so many questions, but why did you write one, though?
It is easier to do this than multiply 100 Times by 19 then divide by 37, then subtract from 100.
Thank you so much!