SmithExam3 - 94 132 120 136 154 132 a Mean 121.75 Standard...

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Olivia Smith Question 1: Mean: 120 5 3 Standard Deviation: 3 Question 2: P(139.50<x<167.25) = P[(139-130)/30]<[(x-mu)/st.dev]<[(167.25-130)/30]  P(0.3<Z<1.24) = 0.3821-0.1075 0.27 OR 27.46% Question 3: standard deviation:30/sqrt(16)=7.5 P(139.50<x<167.25) = P[(139.50-130)/7.5]<[(x-mu)/st.dev]<[(167.25-130)/7.5) P(1.2<Z<4.97) 0.12 OR 11.51% Question 4: For the sample mean, the standard deviation becomes smaller when we increase   the value of n, which then affects the answer from question number two. Question 5: 99% confidence level 0.01 0.01 1 2.58 10 Margin of Error: E=2.58*st.dev/sqrt(n) 2.06 84-2.06<u<84+2.06 Question 6: 90% confidence level 0.1 0.05 0.95 1.64 4.47 Margin of Error: E=1.64*st.dev/sqrt(n) 4.40 58-4.40<u<58+4.40 Question 7: n=number of samples (400) P +/- (z critical value)*sqrt[p*(1-p)]/n number of successes (300) 0.75 +/- 1.96*SQRT[0.75*(1-0.75)]/400 p=population proportion (0.75) [0.708,0.792] Question 8: DDXL does not work in Excel 2008
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Unformatted text preview: 110 96 125 94 132 120 136 154 149 94 119 132 a) Mean 121.75 Standard Deviation 20.36 Critical Value 3.11 at 99% confidence interval Margin of Error 18.25 103.5 <u< 140.0 81.94< u <86.06 53.60< u <62.40 b) I would take the upper part of the confidence interval (140.0) and add thirty Olivia Smith minutes to that time to get 170 minutes. So, the minimum time that a theatre Question 9: a) 95% confidence interval 0.05 0.02 0.98 1.96 8.66 Margin of Error: E=1.96*st.dev/sqrt(n) 112.03 3433-112.03<u<3433+112.03 b) 95% confidence interval 273.86 Margin of Error: E=1.96*st.dev/sqrt(n) 3.54 3433-3.54<u<3433+3.54 c) A) is wider because it has a higher margin of error. manager should plan between start times of movies is 170 min . for typical movies. 3320.97< u <3545.03 3429.46< u <3436.54...
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This note was uploaded on 07/20/2010 for the course MATH 251 taught by Professor Whalen during the Summer '10 term at New Hampshire Community Technical Colleges.

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SmithExam3 - 94 132 120 136 154 132 a Mean 121.75 Standard...

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