(10 points) Using data from 1000 hospital patients, the average length of hospital stay

November 24, 2016

3. (10 points) Using data from 1000 hospital patients, the average length of hospital stay (indays) was modeled as:length = 3.1 + .24 cigarettes – .15 obesity + .86 prescrip – .023 cholesterol (1.5) (.17) (.82) (1.85) (.062)n = 1,000 R2= 0.383 cigarettes: the number of packs of cigarettes smoked per day; obesity: the number of pounds a patient is over the obesity threshold for their age height; prescript: the number of prescription pills taken each day; cholesterol: the patient’s blood cholesterol level.Despite standard errors being high and t-stats being low, an F-test reveals that obesity,prescript, and cholesterol are jointly highly significant. Dropping obesity and cholesterol, theequation is re-estimated as:length = 3.1 + .44 cigarettes + .76 prescrip(1.1) (.21) (.22)n = 1,000 R2= 0.343

a) Calculate the t-statistic on prescrip in the new and old regression.

b) What is the most likely reason that the standard error for prescrip is much lower in thesecond mode

Get a 30 % discount on an order above \$ 50
Use the following coupon code:
COCONUT
Positive SSL