# Lab1 - answer, but you must explain and justify your...

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STAT 350 – Lab #1 Solution For the following problems, use the dataset in this Excel spreadsheet . a. Draw a frequency histogram of the data using the following cutpoints: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100. Note: any observations that fall on a cutpoint should go above that cutpoint (e.g., if 10.00 is an observation, count that in the interval from 10 to 20). 100 80 60 40 20 0 50 40 30 20 10 0 Frequency b. Draw a frequency histogram of the data using the following cutpoints: 0, 2, 4, 8, 16, 32, 64, 100. 1 0 6 4 3 2 8 25 20 15 10 5 0

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c. Draw a density histogram of the data using the following cutpoints: 0, 2, 4, 8, 16, 32, 64, 100. 1 0 6 4 3 2 8 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 Density d. Compare and contrast the three histograms. Which do you think most appropriately/accurately shows the distribution of this data (there is no right/wrong
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Unformatted text preview: answer, but you must explain and justify your choice)? Answers will vary. Clearly the 2 nd histogram is not appropriate, because it appear that there are a large number of observations in the right tail. Both the 1 st and 3 rd histograms show that most of the data is concentrated near zero. The third histogram may technically be the most appropriate because the points are highly concentrated in one region (near zero) but increasingly sparse as you move away from zero, under these conditions, unequal class widths are appropriate (see Lecture #1). e. Describe the shape of the distribution of this graph ( i.e. , is it symmetric, unimodal/bimodal, positively/negatively skewed). The distribution is unimodal and positively skewed....
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## This note was uploaded on 03/09/2010 for the course STAT 350 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

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Lab1 - answer, but you must explain and justify your...

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