Amanufacturer of light bulbs advertises that, on average, its long-life bulb will last more than 4800 hours. to test this claim, a statistician took a random sample of 96 bulbs and measured the amount of time until each bulb burned out. the mean lifetime of the sample of bulbs is 4825 hours and has a standard deviation of 320 hours. can we conclude with 90% confidence that the claim is true?

Aconcession manager at yankee stadium wants to know how temperature affects beer sales. she took a sample of 10 games and recorded the number of beers sold and the temperature in the middle of the game. temperature 80 68 78 79 87 74 86 92 77 84 number of beers 20533 1439 13829 21286 30985 17187 30240 87596 9610 28742 a. draw a scatter plot of the data. b. the manager estimates the regression equation to be: numberofbeers = −100, 678 + 1, 513 ∗ temperature draw this on your scatter plot. c. for one of the estimated points, indicate the residual with ei . d. for that same point, indicate what part of the variation is explained by the model with ˆyi − y¯.