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Formative cycle, higher degree, marketing and advertising, professional module, commercial research, work unit 7, treatment and statistical analysis of the data, associated with the learning result 7.

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Objectives. Learn to calculate the basic measures of descriptive statistics.

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index 1 calculation of the average 2 calculation of the median in this video we are going to learn to calculate

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the average with simple data we see that I have a series of data and I want to calculate the average

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excel has the average function that automatically calculates the average for me I put the same average I

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open parentheses I select all the data I close parentheses I give it to intro and I already have the

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average for simple data. If we remember what the average is, it is the sum of all

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the data divided by the total number of data. We could check that this one

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has done it correctly. If we add all the data here with self-sum, I put here, I give it

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self-sum and automatically I get 193 and to calculate it is equal to the sum of

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all the data 193 divided by the total number of data which is 18 and we have

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checked that the calculated average comes out perfectly as the definition we are going to see

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now the calculation of the average in grouped data we want to obtain information about the level

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of daily consumption of a certain product from the response given by 730 people

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that have been surveyed in several commercial centers the accumulated data obtained that

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are distributed by intervals in terms of daily weight consumption has been the one that

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is reflected in the table where we have daily consumption in interval and absolute frequency we see

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that I do not have the data as such for that reason I have to calculate the class mark which is x

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sub and which is the middle point of the interval how are we going to calculate it because to calculate it we have

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to add the ends of the interval in this case it is 1 plus 5 and the sum we

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divide by 2 and it would give us 3 and so with all the intervals in this case 6

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plus 10 divided by 2 gives us 8 then we already have the class mark the formula

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for the average calculation is the sum of the class mark that we already have

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by the frequency we have made a table here with that calculation of the

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class mark by the frequency and the add-on because we have done the self-sum gives us 10,705 divided

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by the total number of surveyed people, which in this case is the total absolute frequency,

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which is 730 and already the average because it gives me 15 and I would already have calculated the average for grouped data

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we are going to calculate now the median with simple data the median is the value that the

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central place of all the data when these are ordered to calculate it

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excel establishes the function of the median equal to median we open parentheses

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and select all the data that in this case are odd data I close

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parentheses I give it to intro and I have already calculated the median value for

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odd data we are going to calculate we are going to check that that value is correct and

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following the definition we are going to order the data of greater and we check that the central position

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is 10 therefore it has calculated the data of the median correctly with the function equal to

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the median I have 9 data above and 9 data below then the median is the value that

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occupies the central place and this is correct but what happens when the data is even when I have

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one more data, for example, we are going to add one more data so that they are even in this case we are going to

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calculate the median equal to the median I open parentheses and select all the even data I close

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parentheses and give it to intro it has returned me the value of the median which is 9 we are going to check

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if the function has done it correctly by ordering the data from minor to major the data

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that are in the central position are the data of position 10 and 11 in this case what we have

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to do is talk we do the average of the values ​​that are in the center in this case

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are 8 and 10 to calculate the average we divide between 2 and the average would be 9 with which it has

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correctly calculated the data of the median for even data and the median calculation would be done.

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We are now going to calculate the median in grouped data. In the same previous example in which

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we had calculated the median, we are going to calculate the median in the grouped data table.

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We are going to calculate the median using this formula that we had already explained in the previous video.

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When we have ungrouped data, the median is the value that is in the middle when we have

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ordered the data from lower to higher or from higher to lower value. The problem here is that we do not have

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the data as such, we have an absolute frequency table and we cannot calculate it that way.

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For this, what we are going to do is build a table of accumulated frequencies. To this column

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we call it F capital, accumulated frequency. The first value is the value of 100, the second

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value would be the first value plus the second value and so on. The third value is the sum

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of the three values ​​of the frequencies and so on. The final number we obtain is the

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total number of the data of the table as we can check now well we are going to

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calculate n between 2 in this case in between 2 is equal to 730 between 2 that

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gives us a value of 365 we go to the column of

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accumulated frequencies and in this case we look for the first value that is

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greater than 365 which is 434 in 250 it is not greater than 365 so we pass this value therefore

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once we have identified the accumulated frequency we have also identified the

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value of the interval of the median which would be between 11 and 15 therefore l and is the first

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number of the interval that we have just found which would be 11 the capital F we have to

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remember that they refer to the accumulated frequencies and the f minuscule to the absolute frequency

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it is important that we distinguish this to then substitute in the formula therefore the f

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sub i minus 1 is the accumulated frequency of the previous interval, that is, 250 and the is the

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amplitude of the interval in this case is calculated subtracting the limits of the interval we would have

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have to subtract 15 minus 11 and it would be equal to 4 and now we already have all the data

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we need what we are going to do is simply substitute them in the formula so

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that the median would be equal to l sub 0 which would be 11 plus in between 2 which would be 365 minus

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f sub and minus 1 which would be 250 between f minuscule sub and which would be 184 and that gives us a value

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of the average of 13.5 and with this we would have done the calculation of the

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average in grouped data activity defines and calculates the average and the

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average from the following statistics table

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activity calculates the average and the average from the

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following statistics table daily consumption of milk and absolute frequency with

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the following data