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Solved: Arsenic in groundwater. Refer to the
Chapter 12, Problem 127E(choose chapter or problem)
Problem 127E
Arsenic in groundwater. Refer to the EnvironmentalScience & Technology (Jan. 2005) study of the reliabilityof a commercial kit to test for arsenic in groundwater,Exercise 12.16 (p. 682). Recall that you fit a first-ordermodel for arsenic level (y) as a function of latitude (x1),longitude (x2), and depth (x3) to data saved in the file.Conduct a residual analysis of the data. Based on theresults, comment on each of the following:
a. assumption of mean error = 0
b. assumption of constant error variance
c. outliers
d. assumption of normally distributed errors
e. multicollinearity
Questions & Answers
QUESTION:
Problem 127E
Arsenic in groundwater. Refer to the EnvironmentalScience & Technology (Jan. 2005) study of the reliabilityof a commercial kit to test for arsenic in groundwater,Exercise 12.16 (p. 682). Recall that you fit a first-ordermodel for arsenic level (y) as a function of latitude (x1),longitude (x2), and depth (x3) to data saved in the file.Conduct a residual analysis of the data. Based on theresults, comment on each of the following:
a. assumption of mean error = 0
b. assumption of constant error variance
c. outliers
d. assumption of normally distributed errors
e. multicollinearity
ANSWER:
Step 1 of 11
For the given information, a study of the reliability of a commercial kit to test for arsenic
in ground waver. Arsenic level ( y) as a function of latitude (
depth (
a) We have to check the assumption of mean error = 0. That is to check the residuals
plot with predictors.
