Description
1. (HW9 question 3 continued) In biofiltration of wastewater, air discharged from a
treatment facility is passed through a damp porous membrane that causes
contaminants to dissolve in water and be transformed into harmless products. The
accompanying data on x= inlet temperature (°C) and y= removal efficiency (%) was
the basis for a scatter plot that appeared in the article “Treatment of Mixed
Hydrogen Sulfide and Organic Vapors in a Rock Medium Biofilter”(Water
Environment Research, 2001: 426–435). The scatter plot and the summary statistics are
given below.
n=33
Σ (xi)=387
Σ (yi)=3365
Σ (xi-𝑥̅)
2=514
Σ (yi-𝑦̅)
2=6.847
Σ ((xi-𝑥̅)(yi-𝑦̅))=46.578
A. Calculate the fitted regression equation.
B. Interpret the intercept in A.
C. Interpret the slope in B.
D. Obtain a prediction of removal efficiency when temperature=12.
2. Chapter 12, Section 12.5, Exercise 58 parts a b c
Use these summary statistics:
n=12
Σ (xi)=44,615
Σ (xi)
2=170,355,425
Σ (yi)=3,860
Σ (yi)
2=1,284,450
Σ (xiyi)=14,755,500
• Do not forget to interpret the correlation in part (a). Qualify the strength of the linear
relationship between x and y.
• For parts (b) and (c), just say if will increase, decrease, or remain the same. No need to
explain.
