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Question Seven
The air pollution index for fifteen days randomly selected days in summer is
recorded below:
57.6 61.2 59.4 65.6 58.3
44.7 63.2 48.8 55.7 59.0
64.3 43.2 59.7 71.2 45.6
(a) Calculate the sample mean and sample standard deviation for this sample
(b (i)) Round the data to the nearest whole number and construct a stem and leaf
plot of the rounded data
(b (ii)) Are there any strong indcations that the data is not drawn from a normal
distributed population? Explain.
(c) Construct a 98% confidence interval for the population mean air pollution
index
(d) Is it necessary for the recordings of the air pollution index to be normally
distributed for confidence interval in (d) to be valid? Explain.
(e) The environmental Protection Agency would be concerned if the average for
the pollution index was above 55. Set up and conduct a suitable hypothesis to see
if there is any need for the EPA to be concerned about the level of pollution
Question Nine
In computing, “workload ” is defined as a collection of processor and input-output (I/O) resource requests during a particular time. Workloads are compared via a measure called relative I/O content. The base rating is 1. Do the readings below indicate that the installation tested has a workload that is significantly different from the base value?
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0.3
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0.4
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0.7
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0.2
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0.5
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0.6
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1.1
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1.2
|
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1.5
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1.7
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1.4
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1.8
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1.6
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1.2
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1.1
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1.0
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2.0
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2.0
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2.1
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2.2
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1.5
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1.6
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1.0
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1.2
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 The Fug loves to read Now look at the solutions
Questions Seven and Nine
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