In: Statistics and Probability
a. Construct a scatterplot of the data and tell why a linear
regression model is appropriate. (Include this graph in your
report.) b. Run the linear regression procedure on
StatCrunch and include the output in your report. c. Give the
regression equation using the correct notation. d. Give the
Coefficient of Determination AND interpret it. e. Check
the assumptions of the model by constructing each of the following
plots and commenting on what they suggest in terms of the
assumptions. (Include these graphs in your report.) 1. Fitted line
plot 2. QQ-Plot of the residuals 3. Predicted values vs
residuals
f. Test to see if the ‘before reading’ is useful in predicting the
‘after reading’. (Use ? = 0.05.) g. Instruct StatCrunch to save the
95% confidence intervals for the mean response. BUT DO NOT INCLUDE
THE TABLE IN YOUR PROJECT. IT’S VERY BIG. h. Use the
table you created in part g to give the 95% confidence interval for
the average ‘after reading’, when the ‘before reading’ is 60 bpm.
i. Test to see if the ‘before reading’ and the ‘after reading’ are
positively linearly correlated. (Use ? = 0.05.)
NOTE: Opinions may differ on whether or not the assumptions are met. For the sake of instruction, assume you can continue with the linear regression model to complete the project.
Pulse Rate Before (bpm) | Pulse Rate After (bpm) |
89 | 77 |
85 | 70 |
82 | 73 |
58 | 56 |
61 | 58 |
64 | 61 |
60 | 59 |
59 | 57 |
63 | 61 |
61 | 59 |
64 | 62 |
63 | 58 |
68 | 60 |
65 | 65 |
66 | 72 |
60 | 54 |
59 | 55 |
59 | 56 |
60 | 57 |
58 | 57 |
59 | 57 |
82 | 77 |
73 | 68 |
77 | 75 |
75 | 73 |
79 | 75 |
81 | 78 |
78 | 69 |
80 | 72 |
76 | 69 |
90 | 83 |
87 | 82 |
94 | 82 |
92 | 84 |
105 | 86 |
108 | 84 |
85 | 70 |
80 | 67 |
77 | 66 |
83 | 65 |
72 | 69 |
70 | 68 |
75 | 75 |
98 | 87 |
107 | 90 |
103 | 88 |
100 | 84 |
95 | 82 |
105 | 91 |
93 | 88 |
102 | 90 |
110 | 89 |
57 | 41 |
49 | 39 |
50 | 37 |
53 | 49 |
56 | 50 |
49 | 44 |
57 | 55 |
48 | 49 |
50 | 48 |
69 | 65 |
67 | 64 |
68 | 66 |
82 | 64 |
75 | 66 |
79 | 71 |
77 | 76 |
74 | 72 |
76 | 72 |
74 | 74 |
72 | 69 |
75 | 73 |
73 | 77 |
72 | 77 |
70 | 73 |
75 | 62 |
70 | 64 |
72 | 77 |
61 | 46 |
63 | 57 |
64 | 75 |
85 | 57 |
79 | 61 |
77 | 73 |
73 | 67 |
76 | 61 |
78 | 69 |
68 | 64 |
71 | 60 |
77 | 69 |
91 | 84 |
89 | 87 |
86 | 88 |
74 | 69 |
77 | 73 |
76 | 70 |
75 | 57 |
79 | 61 |
73 | 61 |
75 | 59 |
79 | 65 |
72 | 80 |
74 | 70 |
92 | 86 |
66 | 72 |
65 | 66 |
64 | 66 |
62 | 60 |
66 | 70 |
63 | 68 |
Answer using Excel:
a. Construct a scatterplot of the data and tell why a linear regression model is appropriate. (Include this graph in your report.)
b. Run the linear regression procedure on StatCrunch and include the output in your report.
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.858003 | |||||||
R Square | 0.73617 | |||||||
Adjusted R Square | 0.733749 | |||||||
Standard Error | 6.102274 | |||||||
Observations | 111 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 11325.64 | 11325.64 | 304.1442 | 2.57E-33 | |||
Residual | 109 | 4058.914 | 37.23775 | |||||
Total | 110 | 15384.56 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
Intercept | 13.51595 | 3.180927 | 4.249059 | 4.54E-05 | 7.211453 | 19.82044 | 7.211453 | 19.82044 |
Pulse Rate Before (bpm) | 0.733551 | 0.042062 | 17.43973 | 2.57E-33 | 0.650185 | 0.816917 | 0.650185 | 0.816917 |
c. Give the regression equation using the correct notation.
y = 0.733x + 13.51
d. Give the Coefficient of Determination AND interpret it.
R = Coefficient of Defermination = sqrt(R squared) =0.858.
Correlation is positive and strong.
Post remaining questions saperately. Hope thsi will be helpful. Thanks and God Bless You :)