5a-9
I think this is the answer I am a little unsure of what the question is.
1.) top row: 100 200 300 400 500 600. Bottom row: 5 10 15 20 25 30
2. Each ratio is just the top row divided by the bottom row. So the second thing in the ratio would be 200/10, the third one 300/15, etc. Each ratio is equal to 20.
3.) if x is gallons of gas used, y is distance driven. the equation that describes this relationship is y=20x.
Step-by-step explanation: the answer is x = 1/2
Answer:

So then the correct answer is B. $200.
Step-by-step explanation:
Notation
Let X be the average contribution size before John makes his contribution.
Let Y be the total contribution size before John makes his contribution.
Let Z be John's contribution.
We know that for this case $ 75 represent the original average amount before the contribution with 50% increase so we can set up the following equation in order to find the original average amount

And solvong for X we got:

Now we can find the total contribution before the donation with the following proportion:


And then with the formula of average taking in count the 6 values we can find the size of donation Z like this:



So then the correct answer is B. $200.