In: Statistics and Probability
Use SPSS to follow the steps below and conduct a simple linear regression of the following data:
Calories (Xi) |
Sodium (Yi) |
186 |
495 |
181 |
477 |
176 |
425 |
149 |
322 |
184 |
482 |
190 |
587 |
158 |
370 |
139 |
322 |
175 |
479 |
148 |
375 |
State your hypotheses (e.g. HA: “calories will significantly predict sodium”)
Create a scatterplot of the data. State if the scatterplot appears to contain a linear relationship.
Conduct the analysis in SPSS. Include all of the important outputs (e.g. ANOVA Table, Coefficient Table, Regression Table).
State your conclusion regarding the null hypothesis.
Write your conclusion. Include: (i) if there is a significant relationship between calories and sodium, based on the coefficient/slope, and (ii) if the model significantly predicts the sodium level, based upon adjusted R- squared.
6.
Use the results above to create the regression line equation (e.g. Yi = β1Xi + β0).
What numerical value is the slope (β1) associated with calories (Xi)?
What numerical value is the y-intercept (β0) associated with the regression line equation?
Write your regression line equation inserting the numerical slope value and y-intercept value (e.g. Yi = 0.75*Xi + 1.23)
Using the regression line equation from problem 5:
What value is the (predicated) Yi, when Xi = 180?
What value is the (predicated) Yi, when Xi = 155?
What value is the (predicated) Yi, when Xi = 199?
Scatter Plot
From the scatter plot we observe that there is linear correlation between the two variable Sodium Calories.
Model Summary |
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Model |
R |
R Square |
Adjusted R Square |
Std. Error of the Estimate |
1 |
.933a |
.871 |
.855 |
32.64527 |
a. Predictors: (Constant), Calories |
2. Here from the Adjusted R square we observed that ,the model significantly predicts the sodium level.
ANOVAb |
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Model |
Sum of Squares |
df |
Mean Square |
F |
Sig. |
|
1 |
Regression |
57524.691 |
1 |
57524.691 |
53.978 |
.000a |
Residual |
8525.709 |
8 |
1065.714 |
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Total |
66050.400 |
9 |
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a. Predictors: (Constant), Calories |
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b. Dependent Variable: Sodium |
1 . Here from the ANOVA table, we observed that
P value < alpha (level of Significance)
Hence we reject the null hypothesis and conclude that, calories will predict the sodium significantly.
Coefficientsa |
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Model |
Unstandardized Coefficients |
Standardized Coefficients |
t |
Sig. |
||
B |
Std. Error |
Beta |
||||
1 |
(Constant) |
-299.482 |
100.286 |
-2.986 |
.017 |
|
Calories |
4.347 |
.592 |
.933 |
7.347 |
.000 |
|
a. Dependent Variable: Sodium |
The numerical value is the slope (β1) associated with calories (Xi) is 4.347
The numerical value is the y-intercept (β0) associated with the regression line equation is -299.482
Line of regression equation,
Sodium (Y) = 4.347 * Calories – 299.482.
1. What value is the (predicated) Yi, when Xi = 180?
Sodium (Y) = 4.347 * Calories – 299.482.
Sodium (Y) = 4.347 * 180 – 299.482.
Sodium (Y) = 482.978
2. What value is the (predicated) Yi, when Xi = 155?
Sodium (Y) = 4.347 * Calories – 299.482.
Sodium (Y) = 4.347 * 155 – 299.482.
Sodium (Y) = 374.303.
3. What value is the (predicated) Yi, when Xi = 199?
Sodium (Y) = 4.347 * Calories – 299.482.
Sodium (Y) = 4.347 * 199 – 299.482.
Sodium (Y) = 565.571