HW10 inbiofiltration of wastewater

    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.