Module 2 Case.docx - 1 Describe the measures of central...

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1. Describe the measures of central tendency. Under what condition(s) should each one be used? Mean: is the average of a set of data points. Add all the numbers together and then divide by the number of data values. Best used when data is symmetric. Median: is the middle value of the data points. Arrange the data points in ascending or descending order. The median is the middle number. If there is an even number of data points, take the two middle values, add them together and divide by 2. That will give you the median. Best used when data is not symmetric (skewed to the right or left). Mode: is the number that occurs the most of the data points. Best used with nominal data without providing quantitative value. 2. Last year, 12 employees from a computer company retired. Their ages at retirement are listed below. First , create a stem plot for the data. Next , find the mean retirement age. Round to the nearest year. 55 77 64 77 69 63 62 64 85 64 56 59 Stem Leaf 5 5 6 9 6 2 3 4 4 4 9 7 7 7 8 5 Mean: 55+56+59+62+63+64+64+64+69+77+77+85=795÷12=66.25 or 66 3. A retail store manager kept track of the number of car magazines sold each week over a 10-week period. The results are shown below. 27 30 21 62 28 18 23 22 26 28 a. Find the mean, median, and mode of newspapers sold over the 10-week period. 18 21 22 23 26 27 28 28 30 62 Mean: 18+21+22+23+26+27+28+28+30+62 = 285 ÷ 10 = 28.5 Median: 18 21 22 23 26 27 28 28 30 62 = 26+27=53÷2=26.5 Mode: 28
Number of newspapers sold Frequency 18 1 21 1 22 1 23 1 26 1 27 1 28 2 30 1 62 1 b. Which measure(s) of central tendency best represent the data? In this case either one of the measures work. All results are close if not the same.

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