jan_ai
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Distance (d) in km 2 ≤ d < 8 8 ≤ d < 14 14 ≤ d < 20 20 ≤ d < 26 26 ≤ d < 32
Number of persons 10 18 20 30 12

a. Calculate the estimate for the mean distance covered by the walkers.
b. Given that the mode is 22.1 km and the median distance is 19.1 km, comment on the skewness of the distribution.
c. Given that the variance is 53.3, can we be certain that all the distances covered in this sponsored walk are within two standard deviations of the mean? Justify your answer.



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MindMax2000
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a. total of all (mid-point * frequency)/ total frequency
b. mode>median>mean or mode<median<mean. Textbook stuff.
c. standard deviation is the sq rt of the variance. using the mean you found in a) + 2*standard deviation for the larger value. mean - 2* standard deviation for the lower value. Compare the spread of the standard deviations with the range of values you have in the table (including the upper and lower class boundaries).
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