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Math Help - Summation notation

  1. #1
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    Summation notation

    Question. Does anyone have an answer? I'm stumped on these. Thank you
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  2. #2
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    Quote Originally Posted by Y-rag View Post
    Question. Does anyone have an answer? I'm stumped on these. Thank you
    What is the value of each x_i~?
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  3. #3
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    The following is a list of 13 measurements:

    Suppose that these 13 measurements are respectively labeled . (Thus, is labeled , is labeled , and so on.) Does that help? I'm clueless to these.
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  4. #4
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    The way that you ahve this thing written calls for more information necessary to find the solution. What your statement makes is that there are 13 values of x that need to be added together and then divided by 11. But, those values of x are still a mystery. They could be anything. All we know is that there are 13 of them.

    here's what it looks like

    \sum_{i=1}^{13}\frac{x_i}{11}=\frac{x_1+x_2+x_3+x_  4+x_5+x_6+x_7+x_8+x_9+x_{10}+x_{11}+x_{12}+x_{13}}  {11}

    If however you meant to say

    \sum_{i=1}^{13}\frac{i}{11}

    That's different and it looks like this

    \sum_{i=1}^{13}\frac{i}{11}=\frac{1+2+3+4+5+6+7+8+  9+10+11+12+13}{11}

    So, whichever way you meant to write this thing, hopefully I've helped you.
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  5. #5
    No one in Particular VonNemo19's Avatar
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    Well, that helps a bunch! Just take a look at what I've got wrriten. All you gotta do is add all those measurements up and divide by 11!
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  6. #6
    No one in Particular VonNemo19's Avatar
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    \frac{70+(-40)+....}{11}
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  7. #7
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    The following is a list of 13 measurements:
    73, -40, 99, -16, 19, 89, 65, 10, 88, 46, -30, -18, -43

    Suppose that these 13 measurements are respectively labeled . (Thus, is labeled , is labeled , and so on.)
    Find . Round your answer to at least two decimal places.

    #1. Sorry I didn't give you all the info req'd.
    #2. I went out to mow the lawn and get some sanity back.

    Thank you very much for your help.

    Gary

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  8. #8
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    Help

    If I had 12 measurements: 30, -38, -70, -78, 32, 73, 49, -88, 29, 32, 42, 6, and they were labeled x1, x2, x3 etc, how would I find the following?

    Find .

    I added all the numbers, and came up w/19. Then I took x1 which was 30 and added 49 to that and then multiplied that by 19 and came up w/1501 which is the wrong answer. Can anybody help me w/this? Thank you.
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