Benjamin Odei F2021STAT213
Assignment 6 is due on Monday, November 29, 2021 at 11:59pm.
The number of attempts available for each question is noted beside the question. If you are having trouble figuring out your error, you
should consult the textbook, or ask a fellow student, one of the TA’s or your professor for help.
There are also other resources at your disposal, such as the Mathematics Continuous Tutorials. Don’t spend a lot of time guessing – it’s
not very efficient or effective.
Make sure to give lots of significant digits for (floating point) numerical answers. For most problems when entering numerical answers,
you can if you wish enter elementary expressions such as 2 ∧ 3 instead of 8, sin(3 ∗ pi/2)instead of -1, e ∧ (ln(2)) instead of 2, (2 +
tan(3)) ∗ (4 − sin(5)) ∧ 6 − 7/8 instead of 27620.3413, etc.
Problem 1. (1 point) Problem 2. (1 point)
Match the correlation coefficients with their scatterplots. Select The amounts of 6 restaurant bills and the corresponding amounts
the letter of the scatterplot below which corresponds to the corre- of the tips are given in the below. Assume that bill amount is the
lation coefficient. (Click on image for a larger view.) explanatory variable and tip amount the response variable.
? 1. r = −0.74 Bill 52.44 32.98 64.30 106.27 70.29 49.72
? 2. r = 0.76 Tip 7.00 4.50 7.70 16.00 10.00 5.28
? 3. r = 0.22
? 4. r = −0.97 (a) Find the correlation: r =
(b) Does there appear to be a significant correlation?
• A. Yes
• B. No
(c) The regression equation is ŷ = .
A B C D
Answer(s) submitted: (d) If the amount of the bill is $90, the best prediction for the
• amount of the tip is $ .
• Note: Enter your answer as a number xx.xx
•
• (e) According to the regression equation, for every $10 increase
(incorrect) in the bill, the tip should (Enter INCREASE or DE-
CREASE) by $ .
Answer(s) submitted:
•
•
•
•
•
•
(incorrect)
1
, Problem 3. (1 point)
Match the following sample correlation coefficients with the ex-
planation of what that correlation coefficient means. Type the
correct letter in each box.
1. r = .1
2. r=0
3. r = −.97
4. r = −1
A. a weak positive relationship between x and y
B. a strong negative relationship between x and y
C. no relationship between x andy
D. a perfect negative relationship between x and y
Answer(s) submitted:
•
•
•
•
(incorrect)
2
Assignment 6 is due on Monday, November 29, 2021 at 11:59pm.
The number of attempts available for each question is noted beside the question. If you are having trouble figuring out your error, you
should consult the textbook, or ask a fellow student, one of the TA’s or your professor for help.
There are also other resources at your disposal, such as the Mathematics Continuous Tutorials. Don’t spend a lot of time guessing – it’s
not very efficient or effective.
Make sure to give lots of significant digits for (floating point) numerical answers. For most problems when entering numerical answers,
you can if you wish enter elementary expressions such as 2 ∧ 3 instead of 8, sin(3 ∗ pi/2)instead of -1, e ∧ (ln(2)) instead of 2, (2 +
tan(3)) ∗ (4 − sin(5)) ∧ 6 − 7/8 instead of 27620.3413, etc.
Problem 1. (1 point) Problem 2. (1 point)
Match the correlation coefficients with their scatterplots. Select The amounts of 6 restaurant bills and the corresponding amounts
the letter of the scatterplot below which corresponds to the corre- of the tips are given in the below. Assume that bill amount is the
lation coefficient. (Click on image for a larger view.) explanatory variable and tip amount the response variable.
? 1. r = −0.74 Bill 52.44 32.98 64.30 106.27 70.29 49.72
? 2. r = 0.76 Tip 7.00 4.50 7.70 16.00 10.00 5.28
? 3. r = 0.22
? 4. r = −0.97 (a) Find the correlation: r =
(b) Does there appear to be a significant correlation?
• A. Yes
• B. No
(c) The regression equation is ŷ = .
A B C D
Answer(s) submitted: (d) If the amount of the bill is $90, the best prediction for the
• amount of the tip is $ .
• Note: Enter your answer as a number xx.xx
•
• (e) According to the regression equation, for every $10 increase
(incorrect) in the bill, the tip should (Enter INCREASE or DE-
CREASE) by $ .
Answer(s) submitted:
•
•
•
•
•
•
(incorrect)
1
, Problem 3. (1 point)
Match the following sample correlation coefficients with the ex-
planation of what that correlation coefficient means. Type the
correct letter in each box.
1. r = .1
2. r=0
3. r = −.97
4. r = −1
A. a weak positive relationship between x and y
B. a strong negative relationship between x and y
C. no relationship between x andy
D. a perfect negative relationship between x and y
Answer(s) submitted:
•
•
•
•
(incorrect)
2
