A statistics professor was interested in using final lab grades to predict final course grades. She found the following descriptive statistics. Grades are reported as percentages. average lab grade = 75, SD = 20
average final grade= 80, SD = 15, r = 0.60
a) What is the slope of the regression line for her predictions?
b) What is the intercept of the regression line for her predictions?
c) What is the RMS error for her predictions?
d) Predict the final grade for students who earned an 85% in lab.
e) Predict the final grade for students who earned a 65% in lab.
f) Report the percent of students who are predicted to have final grades between 68% and 92%.
g) Select the correct discription.
1. The strength of the correlation may be overemphasized because of the use of rates.
2. This correlation represents an accurate assessment of the effect of lab grades on final grades.
3. A student who skips the labs is predict to have a passing final grade (70% or above).
4. All of the above are true.