#themathhelp

I could tell you easily that if you wanted to use your calculator for this it would be a lot easier on everyone. 

The formula for standard deviation (lowercase sigma) is as follows

Where N is the number of data points you have, Xi is a data point, and mu is your mean. 

I cheat and I use my calculator to help me through it all. So I’m hoping whoever asked this question knows a little on how to get around their calculator but if you don’t… just ask this again with how you want me to help you and I’ll try my best…. So let’s begin.

First, just put all my data into a stat list. Once that is done calculate the 1 variable stats on that list, to get the mean, andN if you don’t already know it. (You can do it the long way too, I like using shortcuts because I’m lazy.) Then use the second list and do an equation for that list L2= (L1- mean)^2. Then I exit out of my list, I use the sum function to sum up the values in L2. Divide that value by N and then square root.

That’s what I normally do, if you’d like to write the steps out it’s basically the same thing except you’re doing it out by hand and instead of the calculator. If you know all the functions and ish…. 

Hope this helps.

I have a quick question for my followers, even those of you who just stumblr (lolololol made a joke) across this. (ohkay maybe not that funny)

But anyways. 

I know there are plenty of math resources out there. 

I'd like to be of greater use to you guys, so would it be useful for me to have quick sum up notes of sections in math courses (i.e algebra, geometry, algebra II, precalc, and calc even higher levels if it was asked of me) while also including other resources?

I'd like to be of greater use to you guys. Seriously. 

So I'm open to suggestions!

On my journey through learning I've hit a snag. I failed Linear last semester, passed calc III and am currently enrolled in Differential Equations. :D 

I'm expanding my knowledge basis to help the greater good.

THANK YOU!

I feel as if I need help with time management. 

I have a lot of free time but it never really occurs to me to do homework with my free time I just waste away doing close to nothing and answering questions on this blog and even that I've been getting behind on. 

First off, I love math and I figure MOST of the time I'm free so might as well. Alright now let's tackle your problem!

The standard form of a linear equation is ax+by=c (I actually had to look that up because I only have used y-int form and slope point. I have no clue why teachers teach standard form I know I personally have rarely used it.)

I find it easiest (and I stress I) to put it in y intercept form to start because I'm used it the most. 

first off we know it's y=mx+5 because b is the y int.

and when y=0 x=3 because that's what an x intercept is. Therefore,

0=m(3)+5 

m=-5/3

So now we have all le elements to make y=-5/3X+5

And not putting it in standard form is easy enough you just move -5/3x to the other side to get

5/3x+y=5

4x^2-8x+3= (2x-1)(2x-3)=0 

Then you apply ZPP (zero product property)

2x-1=0 when x=1/2

2x-3=0 when x=3/2

Which are your answers.