SOLUTION: I am attempting to check my sons answers so I am sorry if these seen easy - they are not to me! Here is the question Tell whether the data shown is direct variation. If so, give

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Question 254340: I am attempting to check my sons answers so I am sorry if these seen easy - they are not to me! Here is the question
Tell whether the data shown is direct variation. If so, give the constant of variation and write the equation'
Time ( hours) 4 5 6 7
Distance(miles) 184 460 828 1288
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
Hi, we can create a table based on the information as
Time ( hours=x) . . . 4 . . . . . . . . 5 . . .. . . . .. 6 . . . .. . . . . 7
Distance(miles=y) 184 . . . .. . . .460 . . . . . . 828 . . .. . . . . 1288
We are looking for a way to get a direct variation model. We need a thing called slope. The equation for that is
m+=+%28y2-y1%29%2F%28x2-x1%29
We take our first two point and find the slope as
m+=+%28460-184%29%2F%285-4%29 => m = 276
We take the second pair and do the same thing:
m+=+%28828-460%29%2F%286-5%29 => m = 368
We take the third pair and do the same thing:
m+=+%281288-828%29%2F%287-6%29 => m = 460.
SInce these numbers are not ALL the same, this is not direct variation.