Reference no: EM132845924

1. Measurements of length and weight for a sample of 20 low birth weight infants are contained in the data set twenty. The length measurements are in the variable length, and the corresponding birth weights in weight.

a. Construct a two-way scatter plot of birth weight versus length for the 20 infants in the sample. Without doing any calculations, sketch your best guess for the least squares regression line directly on the scatter plot (don't cheat and skip ahead to part b!).

b. Now, compute the true least-squares regression line. Draw this line on the scatter plot. Does the actual least-squares line concur with your guess?

c. The outlying point on the scatter plot corresponds to the 9th infant in the sample. Remove this point from the data set. Compute the new least-squares regression line based on the sample of size 19. Look at this fitted regression line. How does the least-squares line change? In particular, comment on the values of the slope and intercept compute this by using STATA with out skipping the process please.