Question 1
True or False.
The value of
R2 is only useful when the number of data points is substantially larger than the number of
β parameters in the model.
◦ True
◦ False
Question 2
As part of a study at a large university, data were collected on
n = 224 freshmen computer science (CS) majors in a particular year. The researchers were interested in modeling
y, a student's grade point average (GPA) after three semesters, as a function of the following independent variables (recorded at the time the students enrolled in the university):
x1 = average high school grade in mathematics (HSM)
x2 = average high school grade in science (HSS)
x3 = average high school grade in English (HSE)
x4 = SAT mathematics score (SATM)
x5 = SAT verbal score (SATV)
A first-order model was fit to data with
R2 = 0.211.
What is the correct interpretation of
R2, the coefficient of determination for the model?
◦ We expect to predict GPA to within approximately .21 of its true value.
◦ Approximately 79% of the sample variation in GPAs can be explained by the first-order model.
◦ We are 79% confident that the model is useful for predicting
y.
◦ Approximately 21% of the sample variation in GPAs can be explained by the first-order model.
(a) Large buttress roots in a tropical rain forest
Science dresses
The large intestine.
How to find the domain of a function (Part 2)
Anatomy of the Large Intestine By the time chyme reaches the large intestine, most of its nutrients
The large, white flowers of giant saguaro cactus (Carnegiea gigantea) produce sweet nectar. The flow