Focus4

# Focus4 - 8532.22 7809.27 7633.52 6621.08 6141.86 5093.68 4143.50 3644.54 1629.74 749.12 414.94 337.46 178.76 129.28 87.79 11.35 31.69 214.04 310.82

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FOCUS EXERCISE 4 Numbers, in order: 24, 28, 29, 35, 38, 45, 52, 56, 76, 89, 96, 98, 103, 105, 107, 113, 122, 131, 134, 138, 164, 164, 164, 170, 176, 176 183, 187, 231, 257 1. Calculate the mean of the “number of years since founding” data. Sum of all numbers: 3491 3491/30 =116.37 2. Calculate the median of the “number of years since founding” data. N = 31 31/2 = 15. 5 (107+113) / 2 =110 3. How do the values you computed in problems 1 and 2 compare, and what do they suggest about the shape of the distribution? The mean is larger than the median. This shows the data is probably very close to being symmetrical, but could be slightly skewed right. 4. Calculate the range of the “number of years since founding” data. 257 – 24 = 233 5. Calculate the standard deviation of the “number of years since founding” data. (Data – sample mean)^2 data
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Unformatted text preview: 8532.22, 7809.27, 7633.52, 6621.08, 6141.86, 5093.68, 4143.50, 3644.54, 1629.74, 749.12, 414.94, 337.46, 178.76, 129.28, 87.79, 11.35, 31.69, 214.04, 310.82, 467.86, 2268.62, 2268.62, 2268.62, 2876.18, 3555.74, 3555.74, 4439.56, 4988.60, 13140.04, 19776.80 n= 30 Sum of data: 113321.04 SQRT (113321.04/(30-1) = 62.51 6. Calculate the interquartile range (IQR) of the “number of years since founding” data. Q1 = 56 Q3 = 164 164 – 56 = 108 7. College of William and Mary was not selected for the sample, but if it were then its number of years since founding value of 313 years would be an outlier. Which of the three statistics calculated in problems 4, 5, and 6 (range, standard deviation, and interquartile range) would be resistant to this outlier value? Interquartile range....
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## This homework help was uploaded on 04/09/2008 for the course STAT 210 taught by Professor Basu during the Fall '06 term at VCU.

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