# quiz1 - = \$400 In 2008 a manager selected a random sample...

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Economics 302 Quiz 1 Spring 2008 Formula 1 1 n i i y y n = = 2 2 1 1 ( ) 1 n i i s y y n = = - - 2 1 1 ( ) 1 n i i s y y n = = - - / y c t s n - - = (n-1) ( / 2) 100(1 )% Confidence Interval for : y t ( / ) s n α μ - ********************************************************************** Answer all questions. Show all work. Reasoning left unexplained will assumed to be reasoning not learned. Good luck. (For Monday, read section 3.1) 1) Define: a) type I error b) causal forecasting model 2) A sample of 10 employees who use child care reveals the following amounts spent last week: 107, 92, 97, 95, 105, 101, 91, 99, 95, 104. Assume that the amounts spent are normally distributed. a) Calculate the sample mean b) Calculate the sample standard deviation. c) Find a 90% confidence interval for , the population mean. d) Is it reasonable to conclude that the typical employee spends at least 105. Explain. 3) In 2007, an insurance company reports that the mean cost to process a claim is

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Unformatted text preview: = \$400. In 2008, a manager selected a random sample of 12 claims processed recently. The sample mean is \$407 and the sample standard deviation is \$6. We want to test at the .01 = level if now 400. a) Set up the null and alternative hypotheses. b) Calculate the test statistic c) Find the rejection point (critical value). d) Test the null hypothesis. e) Find the p-value for your test. Solutions 2. a) 98.6 b) 5.54 c) 9 0.05 98.6 (5.54 / 10) (95.38,101.81) t i = d)not. Since the confidence interval does not include 105, 105 is outside the range of the upper limit. 3 a) : 400 : 400 a H H μ = b) 407 400 4.04 6 / 12 t-= = c) 11 0.005 3.106 t = d) reject H , since 4.04>3.106 e) P value 2*(0.5-0.4990)< α...
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## This note was uploaded on 04/18/2008 for the course ECON 302 taught by Professor Cui during the Spring '08 term at Ole Miss.

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quiz1 - = \$400 In 2008 a manager selected a random sample...

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