WEBVTT
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this question gives you a frequency table and asks you
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to find the mean of the data the values which
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all right as x R 469 and 15. And
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in the frequencies, which all right, it's f
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of each of those values Air six there, six
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fours, 163 nines and to fifteens. Now we
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know from our textbook that the way we find the
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meaning X bar is gonna be the sum of X
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times f for each for each data point divided by
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N and now N is the total number of minutes
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. It's the sample size, the total number of
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data points. And that's the same as the sum
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of F. So I'm gonna write that instead.
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We'll have that. So what I'm gonna do here
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at the bottom of the well, first, I'm
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gonna find X times fr at a column toe a
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frequency table that that is X times F. So
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we'll go ahead through each row. Four times six
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is 24 6 times one is 69 times three is
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27 15 times two is 30. No, at
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a, uh, row at the bottom for the
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some that we're gonna add up our x Times F
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column for numerator and r F Column for a denominator
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and see what we get money out of our F
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column. Six plus one plus three plus to get
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12. So the sum of F is 12 and
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then we add up our X Times F column.
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We get 24 plus six was 27 plus 30 and
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that is 87. So now we know that the
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sum of X Times F is equal to 87 the
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some of, uh, f is just able to
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12. So that means explore is going to be
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equal to 87/12 which is equal to 7.25 and that
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is your final answer.