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?


closed as off-topic by Xander Henderson, max_zorn, Lord Shark the Unknown, user91500, José Carlos Santos Jan 17 at 9:33

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – Xander Henderson, max_zorn, Lord Shark the Unknown, user91500, José Carlos Santos
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    $\begingroup$ 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

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. $$\begin{aligned} -2.33 &= \frac{h-172}{8} \\ -2.33 \times 8 &= \frac{h-172}{8} \times 8 & \text{Cancel division by 8}\\ -2.33 \times 8 &= h-172\\ -2.33 \times 8 + 172 &= h-172 + 172 & \text{Cancel subtraction of 172}\\ -2.33 \times 8 + 172 &= h &\\ h &=-2.33 \times 8 + 172 = 153.36 \approx 153.4\\ \end{aligned} $$

  • $\begingroup$ 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

Not the answer you're looking for? Browse other questions tagged or ask your own question.