1. Application of Basic Statistics:

Comparing the effectiveness of two herbicides (A and B) to control giant foxtail weed

Herbicide A	Herbicide B
Rep	% Control	Dev from mean	(Dev)2	% Control	Dev	(Dev)2	Total
1	85	3.75	14.06	99	1.25	1.56
2	80	1.25	1.56	98	.25	0.06
3	85	3.75	14.06	95	2.75	7.56
4	75	6.25	39.06	99	1.25	1.56
Total	325		68.74	391		10.74	Y..
Mean	81.25			97.75

I. State the null and alternate hypotheses for this research

H_O____________________________________

H_A___________________________________

II. Calculate:

1. Mean ()

Herbicide A ___________________

Herbicide B ___________________

2. Sum of squares (SS)

Herbicide A _____________________

Herbicide B _____________________

3. Variance (S²)

Herbicide A ____________________

Herbicide B _______________

4. Standard deviation (S)

Herbicide A ____________________

Herbicide B _________________

5. Coefficient of variation (CV)

Herbicide A _____________________

Herbicide B ___________________

6. Standard error of the mean (S)

Herbicide A ____________________

Herbicide B ______________________

7. The 95% Confidence Limits (CL)

Herbicide A LL___________UL ________________

Herbicide B LL ___________ UL _______________

8. Establish the confidence intervals (CI) for the two herbicides (for each herbicide draw a line to connect LL to UL).

9. Use the CIs of the two herbicides to make decisions on the null (H₀) and alternate (H_A) hypotheses.

10. Standard Error of the Difference (S_d) ___________________________

11. The degrees of freedom (df) _____________________

12. The t value (calculated) ________________________

13. Critical t (from table at 5%) ________________________

14. Interpret null and alternate hypotheses

15. Calculate the variance within sample (S²_w) ________________________________

16. Calculate the variance between samples (S²_b) ______________________________

17. Calculate the F value ______________________________________

18. Get critical F from F-table __________________________________

19. Interpret null and alternate hypotheses