I don’t have an example question or something in specific to base off of, but I really need help please.
Please have lots of patience with me and can simplify things. I’m struggling in math and appreciate the help. Thank you :)
#How do I do the standard deviation formula?
long wren
sour maple
is this question a how or a why
sour maple
TL;DR: Standard deviation tells us how much our data is spread out, small sd -> values are close together, large sd -> values are all over the place
I'll try to explain using words without funny math symbols
long wren
Ok! Thank you :)
sour maple
(unless you prefer math notation?)
long wren
I have no math understanding , so maybe words please
sour maple
You first gotta find the mean (commonly called "average"), just add your values and divide by count
Then you take each value and subtract the mean giving you a "result"
Then you square each "result" (helps us gets rid of negative numbers + makes large differences even larger)
Then you find the mean of your "results" (add and divide by the number of results)
THen you take the square root of your mean of your "results"
long wren
I understood until the third line. What does you mean square each result. How many results are there? :O
sour maple
The mean of your results yes
long wren
Oh ok. So how would that be with the symbols? I saw the questions and feel overwhelmed :/
sour maple
long wren
I don’t understand that :(
sour maple
basically just tells us that we have to take a sqrt of something
and that something is the (sum of (value minus mean squared))/(count of values)
long wren
I probably would lose points if I don’t use the symbol right? :/
sour maple
No clue how it's graded in psychology lol
in math classes typically not, they usually only care about the result
long wren
in math classes typically not, they usually only care about the result
Ooh ok, that’s probably good then!
Could you give me like a practice question please, I want to try :)
sour maple
99.2, 101.4, 100.1, 98.7, 100.8, 99.8
Calculate the sample standard deviation. Then determine if the batch passes a specification requiring standard deviation ≤ 2.0%.
long wren
How about i calculate it first. I don’t know about the second part :/
sour maple
yes
long wren
How do I make a number a negative on a calculator
sour maple
you put -? but you don't need that here lol
long wren
Oh I have three negative numbers and I haven’t squared rooted yet
sour maple
You first gotta find the mean (commonly called "average"), just add your values ...
Just go step by step and post results for each step
long wren
Ok, so the mean is 600
No
100
Then I subtract 100 from the values
I have -1.3
-0.8
1.4
0.1
0.8
-0.2
I haven’t been able to square root
sour maple
you forgot a step
long wren
What really nooo
sour maple
You first gotta find the mean (commonly called "average"), just add your values ...
Then you square each "result" (helps us gets rid of negative numbers + makes large differences even larger)
sour maple
No you square first
long wren
Square root what?
long wren
I have -1.3
-0.8
1.4
0.1
0.8
-0.2
This?
long wren
What is square and is it different from square root :(
sour maple
sour maple
Yes
sour maple
looks ok
long wren
Did you do all of that just now? So fast?
sour maple
No I used some calculator website lol
and just copy pasted in the numbers I posted earlier
long wren
But I was right!! :D