4. Three sections of elementary statistics were taught by different teachers. A common final examination was given. The test scores are given in the table.

Teacher A	Teacher B	Teacher C
75	90	17
91	80	81
83	50	55
45	93	70
82	53	61
75	87	43
68	76	89
62	58	73
47	82	73
95	98	93
38	64	81
79	64	81
	80	70
	33
	79

Briefly describe the goal of this study in ordinary language, then conduct a hypothesis test at the .05 level of significance. Explain the meaning of the F-ratio and p-value in this context, and summarize results in paragraph form.

5. The accompanying data represents yields per plot for tomatoes grown with three different fertilizers. Seven plots were grown with fertilizer A, eight with fertilizer B, and six with fertilizer C.

A	B	C
31.0	40.0	41.4
31.8	39.6	42.5
28.3	35.3	36.0
29.7	33.0	36.4
28.0	35.7	36.8
27.1	33.7	38.1
32.6	37.4
	38.6

Briefly describe the goal of this study in ordinary language, then conduct a hypothesis test at the .05 level of significance. Explain the meaning of the F-ratio and p-value in this context, and summarize results in paragraph form.