#### Whackyballoon

##### New member

Hi this is probably really simple but if could some one could help this would be nice

6.25 -38 = 7-33.93

they are just ratios but I would like to know what the second unit should be if the first number is 9
eg 9-xxx = 6.25-38= 7-33.93

#### lev888

##### Junior Member
Ratios? Do you mean 6.25/38 = 7/33.93? Doesn't look right to me. Please verify and post your work.

#### Dr.Peterson

##### Elite Member
Hi this is probably really simple but if could some one could help this would be nice

6.25 -38 = 7-33.93

they are just ratios but I would like to know what the second unit should be if the first number is 9
eg 9-xxx = 6.25-38= 7-33.93
It would be really helpful if you explained the context; what you wrote means nothing, but knowing where the numbers come from could help us see what is really going on.

I'm guessing these are meant to be pairs of numbers from a table, like

Code:
6.25   38
7      33.93
9      ???
But I observe that 6.25 × 38 = 7 × 33.93, both being (about) 237.5. (presumably 33.93 is a rounded number, accounting for the slight difference.) So this is an inverse proportion (where the products are equal), not a direct proportion (in which the ratios would be equal). Your hyphens, which look as if they were subtractions, really get in the way of understanding.

Now you want to find a ??? such that 9 × ??? is also equal to 237.5. Can you do that?

#### JeffM

##### Elite Member
Hi this is probably really simple but if could some one could help this would be nice

6.25 -38 = 7-33.93

they are just ratios but I would like to know what the second unit should be if the first number is 9
eg 9-xxx = 6.25-38= 7-33.93

You have not got any helpful answers because (a) you have not done anything that we ask that you do before posting, and (b) your question makes no sense. You say your question is about ratios, but your equation seems to involve subtraction. Did you know that ratios are usually writen either as fractions or using colons?

I am guessing that you are saying 6.25 : 7 :: 33.93 : 38 or, what is the same thing, 6/7 = 33.93/38.

If that guess is right, I should point out that ratios are usually shown with positive integers so the normal way to express this is 625/700 = 3393/3800. More importantly, it is only APPROXIMATELY true.

$$\displaystyle \dfrac{3393}{3800} = 0.8928947 \ne 0.8928571 = \dfrac{625}{700}.$$

Now if I am anywhere close to what you are talking about, let us know. And, given that you posted this in intermediate algebra, is your question

$$\displaystyle \dfrac{625}{700} \approx \dfrac{x}{900} \text { or } \dfrac{625}{700} \approx \dfrac{900}{x} \text {?}$$

EDIT: I see that while I was writing, Dr. Peterson made a guess similar to mine but probably more complete. Please answer our questions so we can be more helpful.

Last edited: