Sample Size = 81 Sample Mean = 4.97 % Sample Standard Deviation = 1.8 %
Does the sample data provide evidence to conclude that the dealership averages more than 4.5 % profit on sales of new cars ( using a = . 10 )? Use the hypothesis testing procedure outlined below .
a . Formulate the null and alternative hypotheses . b . State the level of significance .
c . Find the critical value ( or values ), and clearly show the rejection and nonrejection regions .
d . Compute the test statistic . e . Decide whether you can reject Ho and accept Ha or not . f . Explain and interpret your conclusion in part e . What does this mean ?
g . Determine the observed p-value for the hypothesis test and interpret this value . What does this mean ?
h . Does the sample data provide evidence to conclude that the dealership averages more than 4.5 % profit on sales of new cars ( using a = . 10 )? ( Points : 24 )
1 . ( TCO E ) Bill McFarland is a real estate broker who specializes in selling farmland in a large western state . Because Bill advises many of his clients about pricing their land , he is interested in developing a pricing formula of some type . He feels he could increase his business significantly if he could accurately determine the value of a farmer ’ s land . A geologist tells Bill that the soil and rock characteristics in most of the area that Bill sells do not vary much . Thus the price of land should depend greatly on acreage . Bill selects a sample of 30 plots recently sold . The data is found below ( in Minitab ), where X = Acreage and Y = Price ($ 1,000s ).
a . Analyze the above output to determine the regression equation . b . Find and interpret in the context of this problem .
c . Find and interpret the coefficient of determination ( r-squared ). d . Find and interpret coefficient of correlation .