quiz 7 (1 page)\" STAT351 Section ZA Quiz 7 Name 1 . Below is the plot of standa
ID: 3061857 • Letter: Q
Question
quiz 7 (1 page)" STAT351 Section ZA Quiz 7 Name 1 . Below is the plot of standardized residual vs y after fitting one predictor to predict y 150 250 350 What problem is presented? How to correct this problem? 45 30 25 20 0 5 105 2 25 30 3540 5 2. Above is a scatter plot of a data set (6 observations) with y being the response and x the only predictor. Since there is a curvilinear pattern, a quadratic model with x and x2 as the predictors is fitted. Complete the following ANOVA table. MS 270.9236 0.5509 ssion Residual Total 31.65271 573.5 3. In the general linear model, we can do log(y) or 1/y transformation on y to correct the following problem in the residual plot. 1) curvilinear ii) nonconstant variance iii) linearity iv) multicollinearityExplanation / Answer
1. Residual plot tells us that residuals are trending with increasing x
To correct the problem we would either need to transform the variable or add another variable to take care
of this.
2. df SS MS F
Reg 270.9236
Res 31.65271 10.5509
Tot 573.5
SS Reg = SStotal - SSres = 573.5 - 31.65271 = 541.85
Total df = n-1 = 6-1 = 5
df res = (SSres/MSres) = (31.65271/10.5509) = 3
Therefore df Reg = dftotal - dfres = 5-3 = 2
F = MSreg/MSres = 270.9236/10.5509 = 25.68
3. ii) Non-constant variance
When you have non-constant variance you will have to apply these transformation on y, your dependent variable
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.