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Sample Stat Final, Fall 2007 ( I make no claims that the actual final exam will be like this sample final. However, I do use the sample final as a guide for making up the final exam.) 1) Calculator problem:10 male runners were tested to see if Gator-aid made them run the 100 yard dash any faster. Their times were recorded without gator aid and then the next day with Gator-aid. Do a hypothesis test at the 5% level on the data to see if the Gator-aid made them run faster. ( Use symbols wo and w ) Do this problem with a calculator, show no work. Without GA 11.2 15 13 9 15.1 12 13.7 9.7 11 13 With GA 11 15.2 12.9 9.1 14.9 11.5 12 9.6 10.5 13 H0: __________________________ H1: ______________________ P-value:________ Interpret your results. ______________________ 2) Show all work: The lottery commission wanted to find out if there is a difference in the proportions of men and women who play the lottery. The results are shown below. Find a 93% confidence interval for the difference in the two proportions. Show all work. Sample 1: Men 2: Women x x 1 Z 2 2 X 1600 660 N 5000 3000 ______________________________ Work = _________________ (chart, no work) Error = ___________________ work: Confidence Interval: ___________________work: g) Interpret your results ____________________ 3) Show all work:You do a study of 182 bears and measure the length of their right paws. You get a mean of 12.8 inches and a standard deviation of 3.56 inches. Use your study to test the claim that the population mean of right bear paws is less than 13.1 inches. Use a 6% level of significance. Show all work. H0: ______________________ H1: _______________________ Z x = _______________________ p-value = _______________ Interpret your results. __________________ 4) Paired data is gathered concerning the number of hours a student studies for a statistics test (X) verses the grade on the test (Y). X (hours) 7 2 1 4 3 5.5 Y (grade) 95 60 60 82 62 90 Part I a) make a scatter plot of the data. (hint: increment Y axis into divisions of 10 but start at 50) b) Draw an approximate best-fit line through the points above c) Calculate the best fit line on your calculator: ŷ = _______ + ______x d) Calculate the residual at x = 7 ________________ e) Use your model to find an estimate of the grade earned if you study for 6 hours. f) Find R2 and interpret it’s meaning. R2 = ______________ g) what is the slope__________ interpret it’s meaning:_________________________ h) what is the y intercept ____________ interpret it’s meaning _____________________ Par II Test the significance of the line in part “c” at the 5% level a) P-value:_______ b) Circle one: significant not significant