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.
98.0 98.5 99.0
96.5 97.0 97.5 removal
6 8 10 12 14 16 18
temp
n=33
• (xi)=387
• (yi)=3365
• (xi- ̅)2=514
• (yi- ̅)2=6.847
• ((xi- ̅)(yi- ̅))=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
• (xi)=44,615
• (xi)2=170,355,425
• (yi)=3,860
• (yi)2=1,284,450
• (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.
