Modern medical practice tells us not to encourage babies to become too fat. Is there a positive
Question:
Modern medical practice tells us not to encourage babies to become too fat. Is there a positive correlation between the weight x of a 1-year-old baby and the weight y of the mature adult (30 years old)? A random sample of medical les produced the following information for 14 females:
Σx = 300; Σy = 1775; Σx2 = 6572; Σy2 = 226,125; Σxy = 38,220
(a) Draw a scatter diagram for the data.
(b) Find x, y, b, and the equation of the least-squares line. Plot the line on the scatter diagram of part (a).
(c) Find the sample correlation coefficient r and the coefficient of determination. What percentage of the variation in y is explained by the least squares model?
(d) Test the claim that the population correlation coefficient r is positive at the 1% level of significance.
(e) If a female baby weighs 20 pounds at 1 year, what do you predict she will weigh at 30 years of age?
(f) Verify that Se ≈ 8.38.
(g) Find a 95% confidence interval for weight at age 30 of a female who weighed 20 pounds at 1 year of age.
(h) Test the claim that the slope b of the population least-squares line is positive at the 1% level of significance.
(i) Find an 80% confidence interval for b and interpret its meaning.
Step by Step Answer:
Understandable Statistics Concepts And Methods
ISBN: 9781337119917
12th Edition
Authors: Charles Henry Brase, Corrinne Pellillo Brase