Mean is adding all the numbers then dividing the answer you go from the numbers.
<u>Given</u>:
Given that the figure of similar triangles.
The altitude of the triangle is x.
The length of the left part is 30.
The length of the right part is 15.
We need to determine the value of x.
<u>Value of x:</u>
The value of x can be determined using the geometric mean theorem.
Thus, we have;
![\frac{\text { left }}{\text { altitude }}=\frac{\text { altitude }}{\text { right }}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Ctext%20%7B%20left%20%7D%7D%7B%5Ctext%20%7B%20altitude%20%7D%7D%3D%5Cfrac%7B%5Ctext%20%7B%20altitude%20%7D%7D%7B%5Ctext%20%7B%20right%20%7D%7D)
Substituting the values, we have;
![\frac{30}{x}=\frac{x}{15}](https://tex.z-dn.net/?f=%5Cfrac%7B30%7D%7Bx%7D%3D%5Cfrac%7Bx%7D%7B15%7D)
Cross multiplying, we get;
![30 \times 15= x^2](https://tex.z-dn.net/?f=30%20%5Ctimes%2015%3D%20x%5E2)
![450=x^2](https://tex.z-dn.net/?f=450%3Dx%5E2)
Taking square root on both sides, we have;
![15 \sqrt{2}=x](https://tex.z-dn.net/?f=15%20%5Csqrt%7B2%7D%3Dx)
Thus, the value of x is 15√2
If they get unexpected results they could note what they could've done wrong or what they could change in a next trail of experiments. Or look back and see what different happened to they could've hypothesized. There could be many different courses on what to do next.
![\bf 0.444444444\overline{4}\impliedby \textit{and keeps on going}\\\\ -------------------------------\\\\ \textit{let's say }\boxed{x=0.444444444\overline{4}}\quad \textit{ thus }10\cdot x=4.44444444\overline{4} \\\\\\ \textit{wait a minute! }4.44444444\overline{4}\textit{ is really just }4+0.444444444\overline{4}](https://tex.z-dn.net/?f=%5Cbf%200.444444444%5Coverline%7B4%7D%5Cimpliedby%20%5Ctextit%7Band%20keeps%20on%20going%7D%5C%5C%5C%5C%0A-------------------------------%5C%5C%5C%5C%0A%5Ctextit%7Blet%27s%20say%20%7D%5Cboxed%7Bx%3D0.444444444%5Coverline%7B4%7D%7D%5Cquad%20%5Ctextit%7B%20thus%20%7D10%5Ccdot%20x%3D4.44444444%5Coverline%7B4%7D%0A%5C%5C%5C%5C%5C%5C%0A%5Ctextit%7Bwait%20a%20minute%21%20%7D4.44444444%5Coverline%7B4%7D%5Ctextit%7B%20is%20really%20just%20%7D4%2B0.444444444%5Coverline%7B4%7D)
![\bf \textit{but we know }x=0.444444444\overline{4} \textit{ so then }4+0.444444444\overline{4}=\boxed{4+x} \\\\\\ \textit{wait a second! }10\cdot x\implies 10x=4.444444444\overline{4}=4+x \\\\\\ thus\qquad 10x=4+x\implies 10x-x=4\implies 9x=4\implies \boxed{x=\cfrac{4}{9}}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bbut%20we%20know%20%7Dx%3D0.444444444%5Coverline%7B4%7D%20%5Ctextit%7B%20so%20then%20%7D4%2B0.444444444%5Coverline%7B4%7D%3D%5Cboxed%7B4%2Bx%7D%0A%5C%5C%5C%5C%5C%5C%0A%5Ctextit%7Bwait%20a%20second%21%20%7D10%5Ccdot%20x%5Cimplies%2010x%3D4.444444444%5Coverline%7B4%7D%3D4%2Bx%0A%5C%5C%5C%5C%5C%5C%0Athus%5Cqquad%2010x%3D4%2Bx%5Cimplies%2010x-x%3D4%5Cimplies%209x%3D4%5Cimplies%20%5Cboxed%7Bx%3D%5Ccfrac%7B4%7D%7B9%7D%7D)
you can check in your calculator.
anyhow, to get the "recurring decimal to fraction", you start by setting to some variable, "x" in this case, then move the repeating part to the left of the point by multiplying it by some power of 10, and then do the equating.