In: Statistics and Probability
Use Excel to prepare a Linear Regression Analysis.
Use data samples below for populations and determine if the selected independent variable is affecting the dependent variable. Use an alpha of 5% for ANOVA and Correlation Coefficient. Explain the results.
Data samples
Group A
104,103,101,99,97,101,101
Group B
101,100,95,99,101,103,97
Group C
100,96,99,95,99,102,106
Group D
97,99,99,101,105,100,99
i) Group A and Group B
Regression line equation: y=98.11304347828+0.013043478260679x
Correlation coefficient (r): 0.01130828
SUMMARY OUTPUT | A&B | |||||
Regression Statistics | ||||||
Multiple R | 0.011308 | |||||
R Square | 0.000128 | |||||
Adjusted R Square | -0.19985 | |||||
Standard Error | 2.563316 | |||||
Observations | 7 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 1 | 0.004202 | 0.004202 | 0.000639 | 0.980804 | |
Residual | 5 | 32.85294 | 6.570588 | |||
Total | 6 | 32.85714 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | 99.88235 | 38.56015 | 2.5903 | 0.048819 | 0.760322 | 199.0044 |
X Variable 1 | 0.009804 | 0.387695 | 0.025288 | 0.980804 | -0.9868 | 1.006406 |
ii) Group A and Group C
Regression line equation: y=82.469565217373+0.16956521739148x
Correlation coefficient (r): 0.107523
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.107523 | |||||||
R Square | 0.011561 | |||||||
Adjusted R Square | -0.18613 | |||||||
Standard Error | 2.548618 | |||||||
Observations | 7 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 0.37987 | 0.37987 | 0.058482 | 0.818516 | |||
Residual | 5 | 32.47727 | 6.495455 | |||||
Total | 6 | 32.85714 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 5.0% | Upper 5.0% | |
Intercept | 94.06818 | 28.08963 | 3.348858 | 0.020354 | 21.86149 | 166.2749 | 92.21666 | 95.91971 |
X Variable 1 | 0.068182 | 0.281939 | 0.241831 | 0.818516 | -0.65657 | 0.79293 | 0.049598 | 0.086766 |
iii) Group A and Group D
Correlation coefficient (r): -0.9339
Regression line equation: y=201.29565217391-1.0043478260869x
SUMMARY OUTPUT | A&D | |||||||
Regression Statistics | ||||||||
Multiple R | 0.933915 | |||||||
R Square | 0.872197 | |||||||
Adjusted R Square | 0.846636 | |||||||
Standard Error | 0.916433 | |||||||
Observations | 7 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 28.65789 | 28.65789 | 34.12265 | 0.00208 | |||
Residual | 5 | 4.199248 | 0.83985 | |||||
Total | 6 | 32.85714 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 5.0% | Upper 5.0% | |
Intercept | 187.6992 | 14.87054 | 12.62222 | 5.54E-05 | 149.4733 | 225.9252 | 186.7191 | 188.6794 |
X Variable 1 | -0.86842 | 0.148665 | -5.84146 | 0.00208 | -1.25058 | -0.48627 | -0.87822 | -0.85862 |
iv) Group B and Group C
Regression line equation: y=110.29411764707-0.10784313725499x
Correlation coefficient (r): -0.0788778
SUMMARY OUTPUT | b&C | |||||||
Regression Statistics | ||||||||
Multiple R | 0.078878 | |||||||
R Square | 0.006222 | |||||||
Adjusted R Square | -0.19253 | |||||||
Standard Error | 2.94762 | |||||||
Observations | 7 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 0.271978 | 0.271978 | 0.031303 | 0.866509 | |||
Residual | 5 | 43.44231 | 8.688462 | |||||
Total | 6 | 43.71429 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 5.0% | Upper 5.0% | |
Intercept | 105.1731 | 32.48723 | 3.237367 | 0.023017 | 21.66199 | 188.6842 | 103.0317 | 107.3145 |
X Variable 1 | -0.05769 | 0.326079 | -0.17693 | 0.866509 | -0.8959 | 0.78052 | -0.07919 | -0.0362 |
v) Group B and Group D
Correlation coefficient (r): 0.2208203
Regression line equation: y=79.529411764708+0.20588235294116x
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.22082 | |||||||
R Square | 0.048762 | |||||||
Adjusted R Square | -0.14149 | |||||||
Standard Error | 2.883841 | |||||||
Observations | 7 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 2.131579 | 2.131579 | 0.256306 | 0.634196 | |||
Residual | 5 | 41.58271 | 8.316541 | |||||
Total | 6 | 43.71429 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 5.0% | Upper 5.0% | |
Intercept | 75.74436 | 46.79478 | 1.61865 | 0.166447 | -44.5455 | 196.0342 | 72.65989 | 78.82883 |
X Variable 1 | 0.236842 | 0.467821 | 0.506267 | 0.634196 | -0.96573 | 1.439414 | 0.206006 | 0.267678 |
vi) Group C and Group D
Regression line equation: y=113.40384615385-0.13461538461538x
Correlation coefficient (r): -0.19740215
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.197402 | |||||||
R Square | 0.038968 | |||||||
Adjusted R Square | -0.15324 | |||||||
Standard Error | 3.963082 | |||||||
Observations | 7 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 1 | 3.184211 | 3.184211 | 0.202738 | 0.671371 | |||
Residual | 5 | 78.53008 | 15.70602 | |||||
Total | 6 | 81.71429 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 5.0% | Upper 5.0% | |
Intercept | 128.5188 | 64.30712 | 1.998516 | 0.102133 | -36.7879 | 293.8255 | 124.28 | 132.7576 |
X Variable 1 | -0.28947 | 0.642897 | -0.45026 | 0.671371 | -1.94209 | 1.363145 | -0.33185 | -0.2471 |
a) we have to conclude that Relation between
i) Group A and Group B
ii)Group A and Group C
iii) Group B and Group D this data has no correation between them beacause there correlation value is very low
b) Group A and Group D this two group is strong negative correlation
c) Group B and Group C is moderate neagative correlation between them
d) Group C and Group C is very low negative correlation between them