Theory question 101
Tools of Economic AnalysisSection A (answer one question only from this section)
(a) Explain each of the following measures of central tendency: (i) mean; (ii) median; (iii) mode
(b) Calculate the mean, median and mode of the following set of numbers: 21, 22, 23, 24, 25, 26, 27, 23, 28, 29, 30, 24, 31, 34, 23.
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Model answer
(a)(i) Mean (arithmetic mean): sum of all values divided by the number of values, x̄ = Σx/n.
(ii) Median: the middle value when the data are arranged in order of size.
(iii) Mode: the value that occurs most frequently.
(b) n = 15; Σx = 390; mean = 390 ÷ 15 = 26
Ordered: 21, 22, 23, 23, 23, 24, 24, 25, 26, 27, 28, 29, 30, 31, 34
Median = 8th value = 25
Mode = 23 (occurs three times)
Explanation
Arrange the numbers in order before finding the median.