Question

A Regression methods were used to analyze the data from a study investigating the relationship between the ewe’s weight at time of mating, x (in kg), and her lamb’s offspring 7 months after birth, y (in kg). Summary quantities were n = 20 and

	x		y
mean	52		28
Standard deviation	3.96		3.92
Correlation between y and x		.548

(a). Calculate the least squares estimates of the slope and intercept.

(b). Use the equation of the fitted line to predict what weight be observed for a lamb when the ewe's weight is 53 kg.

(c). What change in mean y would be expected for a 1kg change in x?

(d). Find the coefficient of determination and give an interpretation of it in the context of the

Answer 1

(0) let, slope by & (by/3x) by: 0-544 392 3.96 bi 0:542 Intercept, bo= y ba bp : 28-10.542 • 52) bo 0.184 PS! '. The regression line > 0.184 +0.542 X b) when X = 53 then c) y = -0.184 +0.542 153) y= 29.542 change by I unft then the capficted value of value of y Moreased by 10.542 kg If we х d) 0.54% 7 gr. 013003 30.03 ) of variation Po Approdo hey lambs off spring 7 months Ps explaered by weight at time of mating. after birth