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I'm studying for a finals about probability distribution with Z-table and I got to this part in the example of my lecturer and I have no idea how she arrived to this answer, I've been staring at it and scratching my head for a good 30 minutes and still don't know how she got it. I assume this is probably some basic stuff from high school that I just forgot xD, so please help this stupid college student out haha

-2.33 = h-172/8
h = 153.4

How did she get 153.4?

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    $\begingroup$ Presumably h-172/8 means $\frac{h-172}8$ and not $h-\frac{172}8$. $\endgroup$ – Arthur Jan 16 at 22:44
  • $\begingroup$ Yes, I didn't know how to write a fraction sorry about that :/ $\endgroup$ – Bao Hsu Jan 16 at 22:45
  • $\begingroup$ Can you solve $-2=x/4$ or $-2=(x-15)/4$? $\endgroup$ – Ted Shifrin Jan 16 at 22:48
  • $\begingroup$ @Arthur In fact , in this case, the result is correct when rounded to one digit after the decimal point. $\endgroup$ – Peter Jan 16 at 22:51
  • $\begingroup$ @TedShifrin I cannot, this seems like some basic math stuff, it's so embarrassing that I can't even solve it. Please help this poor guy out. $\endgroup$ – Bao Hsu Jan 16 at 22:53
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Knowledge that is commonly missing in college is fractions and solving equations with a variable. Unfortunately they are assumed to be known, so some dedicated training with them may be required.

I'll step you through the process for this one. $$\begin{aligned} -2.33 &= \frac{h-172}{8} \\ -2.33 \times 8 &= \frac{h-172}{8} \times 8 & \text{Cancel division by 8}\\ -2.33 \times 8 &= h-172\\ -2.33 \times 8 + 172 &= h-172 + 172 & \text{Cancel subtraction of 172}\\ -2.33 \times 8 + 172 &= h &\\ h &=-2.33 \times 8 + 172 = 153.36 \approx 153.4\\ \end{aligned} $$

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  • $\begingroup$ I knew it was just a basic equation! xD Thanks a lot! I'm finally able to understand it now $\endgroup$ – Bao Hsu Jan 16 at 23:03

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