[Interpreting regression modeling results] (4) In a study of human gait analysis

Question

[Interpreting regression modeling results]
(4) In a study of human gait analysis, anthropometric (body measurement) data was collected
on healthy subjects, including height, weight and foot length. Using several of these
measurement, subject body mass index (BMI) was calculated. Subsequently, the researchers
wanted to determine the proportion of variability in BMI explained by anyone of the body
measures. Below is output from a regression analysis of BMI in terms of body weight.
(a) What is the percentage of variability in BMI accounted for by weight?
(b) How many subjects were measured in the study?
(c) Was the one-way data model (with intercept) statistically significant for predicting BMI?
Identify the significance level.
(d) Was body weight a significant predictor of BMI. Identify the significance level.
(e) What might be one problem with the data set used in this analysis?

Response BMI Effect Summary Regression Plot 40 38 36 34 32 BMI 30 28 26 24 20- 110 130 150 170 190 210 230 250 270 Weight Summary of Fit RSquare RSquare Adj Root Mean Square Error1.864756 Mean of Response Observations (or Sum Wgts 1902 0.810258 0.810158 25.20596 Analysis of Variance Sum of Source DF Squares Mean Square FRatio Model Error C. Total 901 34820.359 1 28213.461 1900 6606.898 28213.5 8113.576 3.5 Prob> F .0001 Lack Of Fit Sum of Source Lack Of Fit Pure Error 1875 1653.9289 Total Error 1900 6606.8985 DF Squares Mean Square F Ratio 25 4952.9696 198.119 224.6002 0.882 Prob >F .0001 Max RSq 0.9525 Parameter Estimates TermEstimate Std Error t Ratio Prob>lt Intercept 7.8326067 0.197558 39.65

Explanation / Answer

a) What is the percentage of variability in BMI accounted for by weight?
R^2 = 0.81, hence 81%

(b) How many subjects were measured in the study?
n-1 =1901
n=1902,

(c) Was the one-way data model (with intercept) statistically significant for predicting BMI?
Identify the significance level.
p-value for F < 0.001
hence significant

(d) Was body weight a significant predictor of BMI. Identify the significance level.
p-value for Weight < 0.001
hence
body weight was a significant predictor of BMI

Please rate

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.