The article \"The Undrained Strength of Some Thawed Permafrost Soils\" contained

Question

The article "The Undrained Strength of Some Thawed Permafrost Soils" contained the accompanying data on the following.

y = shear strength of sandy soil (kPa)
x1 = depth (m)
x2 = water content (%)

The predicted values and residuals were computed using the estimated regression equation where x3 = x12, x4 = x22, and x5 = x1x2

(a) Use the given information to compute SSResid, SSTo, and SSRegr. (Round your answer to four decimal places if needed.)

(b) Calculate R2 for this regression model. (Round your answer to three decimal places if needed.)
R2 =  

(c) Use the value of R2 from Part (b) and a 0.05 level of significance to conduct the appropriate model utility test. (Round the answer to two decimal places.)
F =

SSTo =   SSResid =   SSRegr =  

Explanation / Answer

The regression analysiis output is as follows

Hence from the above analysis

a)

b) R2 value is given by R2 = 0.759

c) The F value is F = 5.03

Since the p - value for this model is 0.02 < 0.05(significance level ) we can conclude that the model appropriate to given data.

SUMMARY OUTPUT Regression Statistics Multiple R 0.8709755 R Square 0.759 Adjusted R Square 0.6077221 Standard Error 6.9878337 Observations 14 ANOVA df SS MS F Significance F Regression 5 1227.5707 245.514145 5.03 0.0222 Residual 8 390.6386 48.8298201 Total 13 1618.2093 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept -151.36 134.07 -1.13 0.29 -460.52 157.81 X -16.22 8.83 -1.84 0.10 -36.58 4.15 Z 13.48 8.19 1.65 0.14 -5.40 32.35 XX 0.09 0.07 1.32 0.22 -0.07 0.26 ZZ -0.25 0.13 -1.99 0.08 -0.55 0.04 XZ 0.49 0.23 2.16 0.06 -0.03 1.02

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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