scan00011

Analysis of Variance

Model II - example

,v

13309

-L

XJ

Step 1 - Preliminary computations

	host 1	host 2	host 3	6»*4	5/
	2978	3544	4619	2168	13 30*
■i	8	10	13	6	i
Y,	372.25	354.40	355.31	361.33	359.70
£(y,-v,)-	379.50	1278.4	954.77	1165.3	3778.0 r-t-4_

"7^

Width (in |im) of scutum (dorsal shield) of larvae of the tick Haemaphysa/is łeporispalustristn samples from 4 cottontail rabbits

Source: Sokat and RoMf, Bomelry

host 1	Kost 2	Kost 3	Kost 4
3*0	350	354	376
376	356	360	344
360	358	362	342
368	376	352	372
372	338	366	374
366	342	372	360
374	366	362
382	350	344
	344	342
	364	358
		353
		348
		348

Step 2 - Sum of squares

SS, , sum of squares among groups =

8(372.25 - 359.7)² +10(354.4 - 359.7)² +... + 13(355.31 -3S9.7)² +6(361.33-359.7)² =

1807.73

Step 2 - Sum of squares		| Step 2 - Sum of squares
SS^,^, sum of squares within groups =		"T SSlouU, total sum of squares =
±±(\-xf-
i-i j-i		1807.73 + 3778.0 = 5585.73
379.50 + 1278.40 + 954.77 +1165.33 = 3778.0