16. The following scatter plot graphs the average final grade students received in Introduction to Biology (V) versus the number of days they were absent during the semester (x). Also displayed are...

Extracted text: 16. The following scatter plot graphs the average final grade students received in Introduction to Biology (V) versus the number of days they were absent during the semester (x). Also displayed are the best fit line, the equation for that line, and the R² value corresponding to the data. Just to make sure you understand: the point on the very right, for example, indicates that missing x = 9 days of class resulted in an average grade of y = about 66. 100 90 80 70 60 50 y = -2.8x + 88.7 R2 = 0.8976 40 30 20 10 4 8 10 a) Does this graph show a positive, negative, or zero correlation? How can you tell? b) Is this correlation strong or weak? How can you tell? c) Interpret the y-intercept of the line: 88.7. In words, what does this number represent? Hint: the y-intercept is the value of y when x = 0. d) Interpret the slope of the line: –2.8. In words, what does this number represent? Hint: the slope is how much y is gained or lost per single increase in x.


Extracted text: 16. Missing class, continued e) Interpret the R2 value: 0.8976. This number is fairly close to 1 – what does that tell us? f) Either by using the equation or by drawing the line out further, predict the grade of a student who was absent for 10 days throughout the semester. g) Consider the following two statements: (1) "This graph proves that missing classes causes a student's grade to be lower." (II) "This graph proves that there is a correlation between a student's attendance and final grade." Are both statements accurate, or is only one of them accurate, or are neither of them accurate? Be sure to explain your answer.