Final answer:
To calculate the residual, you need the regression equation for the study, then subtract the predicted body fat percent from the observed body fat percent of 11.3.
Step-by-step explanation:
To find the residual for the man in the study with a neck circumference of 38.7cm and a body fat percent of 11.3, we would need the actual equation of the regression line for these variables. The residual is the difference between the observed value and the predicted value given by the regression equation.
For example, if the regression equation predicting body fat percent from neck circumference is:
Body Fat Percent = a + b(Neck Circumference),
where a and b are the regression coefficients obtained from the sample data of college freshman males,
then to compute the residual, we would substitute the observed neck circumference into the equation to find the predicted body fat percent and subtract this predicted value from the observed body fat percent of 11.3.
The formula for calculating the residual (r) is:
r = observed value - predicted value.