Asked by Patrick
Hello. If I have the following table:
Time(x) 18 27 72 81
Distance (y) 8 12 32 36
How would I create an equation relating the variables in the table?
y=
Please help. I have never done this before?
Time(x) 18 27 72 81
Distance (y) 8 12 32 36
How would I create an equation relating the variables in the table?
y=
Please help. I have never done this before?
Answers
Answered by
Henry
d = r * t.
8 = r * 18, r = ?.
12 = r * 27, r = ?.
32 = r * 72, r = ?.
8 = r * 18, r = ?.
12 = r * 27, r = ?.
32 = r * 72, r = ?.
Answered by
Steve
check for a common ratio of changes. For example,
(12-8)/(27-18) = 4/11
(32-12)/(72-27) = 20/55 = 4/11
so, it appears that the line has a constant slope of 4/11
Now, using any of the given points, plug into the point-slope form of a line:
y-8 = 4/11 (x-18)
or
11y-88 = 4x-72
11y = 4x+16
y = (4x + 16)/11
etc.
To be thorough, though, you might want to check the other intervals. If the slope changes, then the equation will not be so simple.
(12-8)/(27-18) = 4/11
(32-12)/(72-27) = 20/55 = 4/11
so, it appears that the line has a constant slope of 4/11
Now, using any of the given points, plug into the point-slope form of a line:
y-8 = 4/11 (x-18)
or
11y-88 = 4x-72
11y = 4x+16
y = (4x + 16)/11
etc.
To be thorough, though, you might want to check the other intervals. If the slope changes, then the equation will not be so simple.
Answered by
Steve - Ouch
I made a typo.
Maybe Henry's solution will be better. Either approach will work if done carefully.
Maybe Henry's solution will be better. Either approach will work if done carefully.
Answered by
Reiny
Steve's slope calculations should have resulted in 4/9
so continue with:
y-8 = (4/9)(x-18)
so continue with:
y-8 = (4/9)(x-18)