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點做?????standard deviation and
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Question 1The numbers of hours spent by a sample of 27 students in studying for an examination are as follows:118251873229181821251822125301915205025102623121617 (a) Set up a stem-and-leaf display for these data. (b) Compute the mean, mode and median. (c) Compute the range, first quartile, third... 顯示更多 Question 1The numbers of hours spent by a sample of 27 students in studying for an examination are as follows:118251873229181821251822125301915205025102623121617 (a) Set up a stem-and-leaf display for these data. (b) Compute the mean, mode and median. (c) Compute the range, first quartile, third quartile, interquartile range, standard deviation and coefficient of variation. (d) Construct a box-and-whisker plot and describe the shape.
最佳解答:
2 5 5 7 8 10 11 12 12 15 16 17 18 18 18 18 19 20 22 23 25 25 25 26 29 30 32 a) Stem| Leaf 0 | 25578 1 | 012256788889 2 | 02355569 3 | 02 b) mean = (2+5+5+7+8+10+11+12+12+15+16+17+18+18+18+18+19+20+22+23+25+25+25+26+29+30+32)/27 = 468/27 = 17.3333 mode = 18 median(14th) = 18 c) range = 32-2 = 30 first-quartile = 11 third-quartile = 25 inter-quartile range = 25-11 = 14 variance = (2^2+5^2+5^2+7^2+8^2+10^2+11^2+12^2+12^2+15^2+16^2+17^2+18^2+18^2+18^2+18^2+19^2+20^2+22^2+23^2+25^2+25^2+25^2+26^2+29^2+30^2+32^2-27*(17.3333)^2)/(27-1) = 1720/26 = 66.1539 sd = sqrt(variance) = sqrt(66.1539) = 8.1335 coefficient of variation = sd/mean = 8.1335/17.3333 = 0.4692 d) 圖片參考：http://imgcld.yimg.com/8/n/HA00039834/o/701111220066713873403990.jpg The shape is quite symmetric and evenly spread. No outlier is found.
其他解答:6CC7293C79127CE5
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