Question

ante 7. You are a researcher interested in the relationship between age of an infant (in months) and hours spent sleeping. Suppose that you sampled N - 10 infants between the ages of 1 - 12 months. After fitting a simpler linear regression model, you found that the intercept of your begression line was 14.72 and the slope was 0.24. (a) Write the regression equation for predicted scores. Include the parameter estimates and informative labels (i.e., use 14.72,-0.24 hours sleep, and age instead of a, b, zor ). (b) Interpret the slope and intercept in the context of the question being asked (i.e., don't only state the numerical value of each, but state what that number means in terms of babies' age and sleep). (e) Predict the number of hours that a 6 month-old will sleep. If you should not trust this prediction, explain your reasoning. (d) Predict the number of hours that a 21-month-okl will sleep. If you should not trust this prediction, explain your reasoning

Answer 1

Question 7

Here the regression equation is

Hours Sleep^ = 14.72 - 0.24 * age

(b) Here intercept is the predicted amount of sleep of an infant who just born. So, an infant who just born will take 14.72 hours of sleep.

Slope here is the decrease in predicted amount of sleep when the age is increase by one unit. So, increasing one month age of infant would reduce the predicted age by 0.24 hours.

(c) Here for x = 6

y^ = 14.72 - 0.24 * 6 = 13.28 hours

we should trust this prediction as values of independent variable is inside the range of x values.

(d) Here for 24 month old sleep,

y^ = 14.72 - 0.24 * 24 = 8.96 hours

we shouldn't trust this prediction as values of independent variable is not inside the range of x values.