We Wish to Compare Three Brands of Golf Balls with Respect to the Distance They Travel

Sample Stat Final, Fall 2007 ( I make no claims that the actual final exam will be like this sample final. However, I

Microsoft Equation do use the sample final as a guide for making up the final exam.) 3.0

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 With GA 11.2 11 15 15.2 13 12.9 9 9.1 15.1 14.9 12 11.5 13.7 12 9.7 9.6 11 10.5 13 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 X N 1: Men 1600 5000 2: Women 660 3000

  ______Work x1x2

Za = ______(chart, no work) 2 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) Y (grade) 7 95 2 60 1 60 4 82 3 62 5.5 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: yˆ = ______+ ______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