When x=8,y=20. Find y when x=42
As Andy said, there are many ways of looking at this:
Setting up a proportion gives us...
8 is to 20 as 42 is to y
8/20 = 42/y
8y = 20(42)
y= 20(42)/8
y = ____
If this is a direct relation:
y = kx
20 = 8k
k = 20/8
k = 2.5
y = 2.5x
y = 2.5(42)
y = _____
Note: This should be the same answer as the proportion gave.
Then of course, there is the question of whether you are trying to
find a geometric or arithmetic series or sequence with a pattern ....
Thus, Andy C's response.