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 2 4 6 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.

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
Practice Pack
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.
Transcribed Image 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.
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.
Transcribed Image 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.
Expert Solution
video

Learn your way

Includes step-by-step video

steps

Step by step

Solved in 3 steps with 1 images

Blurred answer
Similar questions
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman