Q1) You are attempting to prove that variance of dollar value of products purchased on line for certain target market is greater than $100. To test this you choose a random sample of 20 customers and determine that variance of this sample is $150.
a) Set up hypotheses and test to find out whether or not population variance is larger than $100.
b) Based on your sample variance, create a 95% confidence interval, which will contain the true variance 95% of the time. This is, of course, by definition of confidence interval.
Q2) 3 methods of treating water were undertaken at 2 different water treatment plants. Each method was tried for one month and a score (from 1 to 100) was assigned by plant managers on effectiveness of the method (100 is maximum effectiveness).
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Treatment Method
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Plant Types
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(1)
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(2)
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(3)
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Plant 1
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46
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74
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61
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|
Plant 2
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52
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78
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67
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a) Use randomized block analysis of variance to test if there is difference in means of 3 methods and between two plants.
b) If methods vary then employ the Tukey procedure to find out which treatments are more effective relative to each other.