Question

QUESTION 12 For a project in his statistics class, a student is attempting to create a formula for the number of cars in the dorm parking lot that are either sedans, SUVS or pickup trucks. His formula states that there should be 20% sedans, 559% SUVS and 25% pickups. To validate his formula, he finds the following actual values for the 100 vehicles in the lot Sedan: 25 SUV: 45 Pickup: 30 alpha value of .05 Can we believe that his formula is correct? Use an

Answer 1

Answer Chi square test for goodness of fit: Ho pi 0.2, p2-0.55, p3=0.25 Ha: At least one of the proportions is different from the above distribution (i.e. data does not fit the given distribution) Observed(fo) pi Expected(fe) (fo-fe)2/fe Sedans 25 0.2 20 1.250 SUVS 45 0.55 55 1.818 Pickups 0.25 1000 30 25 Total 100 1 100 4.068 Test statistic Chi square 4.068 df 3-1-2 p-value CHIDIST (4.068, 2)=0.1308 we fail to reject the null hypothesis As p-value is greater than 0.05, There is not sufficientevidence to conclude that distribution is not correct Yes, we can believe that his formula is correct