I Need help finding the sum of the differences squared.

#1
Hello everyone,

I would love if someone can hep me solve this problem without the use of a calculator. I am stuck right in the middle, I know how to find the mean of the sample, however I do not know is how to find the sum of the differences squared. That is where i got stuck, from there on I can do on my own. If someone can show me the steps to find the sum of the differences squared it would be awesome.
Screen Shot 2018-04-30 at 9.50.12 PM.png Screen Shot 2018-04-30 at 9.50.21 PM.png Screen Shot 2018-04-30 at 9.50.12 PM.png Screen Shot 2018-04-30 at 9.50.21 PM.png Need
 
#2
Like you can google, the calculation for Sum of Squares is ∑(xi – x̄)2
Please try to draw it graphically. I assume you know how to draw "xi – x̄"? and then draw a square?
 
#4
Please show me what you did for the first left point. what is x1? what is x̄ ? what is (x1 – x̄)^2?
 
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#5
The formula advised for this question is (x-x̄)^2 and not (x1 – x̄)^2

so far I know n-16-=15
x̄=74.3125

(x-74.3125)^2
I do not know how what x is as of now, thats where I am stuck and where I am asking help, if you can show me the google search that you were able to find examples it would be greatly appreciated, I really do not need the answer just need examples so I can do it on my own.

thanks
 
#7
Thank you so much for helping out and giving an example on how to do it, I tried most options but never got the right answer.

In this case there was no explanation to do this part when clicking on the questions mark.
 
#8
Did you click on the button for 'Sum of squares'? The last part of the explanation there explains how to compute the sum of squares total. In short, you compute the difference between each score and the overall mean (74.3125 in your case), square each difference score, and then sum all these squared differences.
 
#9
The question mark you are referring to is there to help you and answer questions you have related to mymathlab, how to use the program.

There is an option which says "question help" which is above the question, and it is not pictured in the image I posted, there you can find examples on how to solve the questions and other options like how to solve the questions, which I tried both and there was no info on how to do the "sum of square, only if I am missing something?!?!?1
 
#10
Did you click on the link I posted? The link is not related to mathlab. I think you were at the wrong website.

But again: try to compute the difference between each of the scores and the overall mean, square these differences, and then sum the squared differences. That's all you need to do to find the sum of squares.