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Analyze the data sets below. Data Set A Data Set B 25 26 27 28 29 30 31 32 33 34 35 25 26 27 28 29 30 31 32 33 34 35 Which of the following statements are true? Select all that apply. Data Set A is relatively symmetric and Data Set B is skewed left. The means of the data sets are within 3 units from each other. The data sets have the same standard deviation. The mean of Data Set A is 27.95 and the mean of Data Set B is 30. O Type here to search

1 Answer

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We need to find the mean of the 2 data set. For data set A, we get


\operatorname{mean}=(3\cdot25+3\cdot26+27+2\cdot28+29+30+2\cdot31+32+2\cdot33+34+3\cdot35)/(20)

which gives


\operatorname{mean}=(594)/(20)=29.7

The mean fot data set B is


\operatorname{mean}=(3\cdot25+4\cdot26+4\cdot27+2\cdot28+2\cdot29+30+2\cdot31+32+34)/(20)

which gives


\operatorname{mean}=(559)/(20)=27.95

By means of these results, we can cancel out options 2 and 4.

Lets find the median for data set A. The median is the middle number in the sorted. For set A the median is between the 10th number and 11th number, that is, its between 29 and 30. Then the median is


\operatorname{median}=(29+30)/(2)=29.5

Similarly, the median for data set B is between 10th number and 11th number, that is,


\operatorname{median}=(27+27)/(2)=27

So, we can conclude for data set A that the mean and median are close in value because mean=29.7 and median=29.5. Which corresponds to option 6.

Now,

- option 1 is incorrect because data set B is skewed right.

- option 2 is incorrect because mean for A is 29.7 and for B is 27.95

- option 3 is incorrect because the values of set A are more spread than set B

- option 4 is incorrect for the same reason than option 2

- option 5 is correct for the same reason that option 3 and because the values for set B are more focalized around the mean.

- option 6 is correct because for data set A the mean and median are close in value: mean=29.7 and median=29.5

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