Question 668443
the Chief wants to know which neighborhood has the highest mean number of calls for service per day over the past year. Unfortunately, two neighborhoods have a mean of 18 calls per day. Neighborhood A has an s of 12.23 and Neighborhood B has an s of 7.42. Using a 95% confidence level, calculate confidence intervals for both neighborhoods and then discuss which neighborhood you believe needs the extra patrols and why.
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A-CI:
18-1.96[12.23/sqrt(n)] < u < 18+1.96[12.23/sqrt(n)]
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B-CI:
18-1.96[7.42/sqrt(n)] < u < 18+1.96[7.42/sqrt(n)]
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Because 12.23 is larger than 7.42 the A-CI will have a greater
range than the B-CI.  The true mean may reach a higher level
for neighborhood A than for neighborhood B. A should be assigned
extra patrols.
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Cheers,
Stan H.
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