Question 14.3 (Page 611) – A random sample of the following two variables was obtained: x 29 48 28 22 28 42 33 26 48 44 y 16 46 34 26 49 11 41 13 47 16 (a). Calculate the correlation coefficient between these two variables. (b). Conduct a test of hypothesis to determine if there exists a correlation between the two variables in the population. Use a significance level of 0.10. (c). Fit the regression equation of Defects (y) on Production rate (x)

The data is given as follow. xi 2 6 9 13 20 Vi 7 18 9 26 23 The estimated regression equation for these data is y7.6 + .9x. Compute SSE, SST, and SSR (to 1 decimal) SSE SST SSR What percentage of the total sum of squares can be accounted for by the estimated regression equation (to 1 decimal)? What is the value of the sample correlation coefficient (to 3 decimals)?

Suppose a doctor measures the height, x, and head circumference, y, of 11 children and obtains the data below. The correlation coefficient is 0.883 and the least squares regression line is y = 0.134x + 13.693. Complete parts (a) and (b) below. Height, x Head Circumference, y 17.4 27.75 25.25 26 25.25 27.25 26.75 26 27.25 27 27.25 26.75 17.1 17.3 17.0 17.4 17.2 17.2 17.3 17.3 17.4 17.3 ..... (a) Compute the coefficient of determination, R?. R? % (Round to one decimal place as needed.) (b) Interpret the coefficient of determination. Approximately % of the variation in is explained by the least-squares gression model. (Round to one decimal place as needed.)

The U.S. Department of Energy’s Fuel Economy Guide provides fuel efficiency data for cars and trucks. The following regression output was obtained for a sample of 45 cars. The variable of interest is highway miles per gallon (Hwy MPG). The independent variables used in the analysis are as follows: The class of the vehicle: Compact, Midsize or Large. Midsize = 1 if the car is a midsize, 0 otherwise. Similarly, Large = 1 if it is a large car, 0 otherwise. Displcement: The engine displacement (size) in liters Premium: Equals 1 if premium fuel is used, 0 if regular fuel is used Cylinders: Number of cylinders   Regression Statistics             Multiple R 0.90           R Square             Adjusted R Square 0.79           Standard Error 1.78           Observations 45                         ANOVA               df SS MS F Significance F…