#40

The quantity of dissolved oxygen is a measure of water pollutionin lakes, rivers, and streams. Water samples were taken at fourdifferent locations in a river in an effort to determine if waterpollution varied from location to location. Location I was 500meters above an industrial plant water discharge point and near theshore. Location II was 200 meters above the discharge point and inmidstream. Location III was 50 meters downstream from the dischargepoint and near the shore. Location IV was 200 meters downstreamfrom the discharge point and in midstream. The following tableshows the results. Lower dissolved oxygen readings mean morepollution. Because of the difficulty in getting midstream samples,ecology students collecting the data had fewer of these samples.Use a 5% level of significance. Do we reject or not reject theclaim that the quantity of dissolved oxygen does not vary from onelocation to another?

Location I	Location II	Location III	Location IV
7.3	6.6	4.6	4.8
6.2	7.1	5.2	5.1
7.4	7.6	4.8	6.9
6.5	8.2	5.6
6.8		4.3

(b) Find SS_TOT, SS_BET, andSS_W and check that SS_TOT =SS_BET + SS_W. (Use 3 decimal places.)

SSTOT	=
SSBET	=
SSW	=

Find d.f._BET, d.f._W,MS_BET, and MS_W. (Use 3 decimalplaces for MS_BET, andMS_W.)

dfBET	=
dfW	=
MSBET	=
MSW	=

Find the value of the sample F statistic. (Use 3 decimalplaces.)


What are the degrees of freedom?
(numerator)
(denominator)

(f) Make a summary table for your ANOVA test.

Source of Variation	Sum of Squares	Degrees of Freedom	MS	F Ratio	P Value	Test Decision
Between groups					p-value < 0.001	---Select--- Do not reject H0. Reject H0.
Within groups
Total