Hayden wants to know if the residents in his town are interested in having a recreation center built. Which sample would allow Hayden to make a valid conclusion? A.
asking the children living in town

B.
asking the people living on his street

C.
asking 50 randomly chosen people living in the town

D.
asking a random group of 50 parents at a school meeting in town

What is the ratio of the length of an object in yards to the length of the same object in miles?

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.

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¯.