hw1_sol - Solution to Homework #1 (80 points) Due in...

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1 Solution to Homework #1 (80 points) Due in class9/2/2010 1. (5pts) What is the login name of your blackboard account? 2.(8pts) In a study of schizophrenia, researchers measured the activity of the enzyme monoamine oxidase (MAO) in the blood platelets of 18 patients. The results (expressed as nmoles benzaldehyde product per 10 8 platelets) were as follows: Construct a frequency distribution and display it as a table and as a histogram. Bins (2) ; Frequencies (2) ; Histogram (2) ; Histogram labels (2) First decide on the bins or classes to use. range = largest observation - smallest observation = 18.8 - 4.1 = 14.7 Use between 5 and 15 bins; increase the range so it divides evenly by the number of bins. [Any number of bins from 5 to 15 is correct, but I imagine 5, 6, 8, and 10 will be common choices, so I'll give the solutions for those. Only one of these is required.] Using 5 bins: round up the range to 15. Then bin width = range/#bins = 15/5 = 3.0. Using 6 bins: round up the range to 15. Then bin width = range/#bins = 15/6 = 2.5 Using 8 bins: round up the range to 16. Then bin width = range/#bins = 16/8 = 2.0. Using 10 bins: round up the range to 15. Then bin width = range/#bins = 15/10 = 1.5. The starting point should be a round number 4.1. Choose 4.0 for all #bins. 5 bins Freq 6 bins Freq 8 bins Freq 10 bins Freq 4.0-6.9 3 4.0-6.4 2 4.0-5.9 2 4.0-5.4 2 7.0-9.9 8 6.5-8.9 7 6.0-7.9 5 5.5-6.9 1 10.0-12.9 4 9.0-11.4 4 8.0-9.9 4 7.0-8.4 5 13.0-15.9 2 11.5-13.9 2 10.0-11.9 3 8.5-9.9 3 16.0-18.9 1 14.0-16.4 2 12.0-13.9 1 10.0-11.4 2 16.5-18.9 1 14.0-15.9 2 11.5-12.9 2 16.0-17.9 0 13.0-14.4 1 18.0-19.9 1 14.5-15.9 1 16.0-17.4 0 17.5-18.9 1 Total 18 Total 18 Total 18 Total 18 6.8 8.4 8.7 11.9 14.2 18.8 9.9 4.1 9.7 12.7 5.2 7.8 7.8 7.4 7.3 10.6 14.5 10.7
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2 [The end points of the bins could have more digits, e.g. 4.0-6.99 or 4.0-6.999 and still be correct. However, 4.0-7.0 would be incorrect for a bin width of 3 since that would be overlapping.] [Students may also give relative and/or percent frequency in their answers. This is correct but not necessary for full credit.] Now draw a histogram corresponding to the frequency distribution. [The histogram should have an overall title of something like “MAO activity in schizophenia”.
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hw1_sol - Solution to Homework #1 (80 points) Due in...

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