Question

Teacher ratings; grades professor stone a teacher who gives good grades gets good ratings, and a teacher who gives bad grades gets bad ratings. test this claim random sample of 300 teacher ratings test the hypothesis excellent 14 18 15 3 average 25 35 75 15 poor 21 27 40 12

Answer 1

Ans:

Chi square test for independence:

	Observed(fo)
Rating	A	B	C	F	Total
Excellent	14	18	15	3	50
average	25	35	75	15	150
poor	21	27	40	12	100
Total	60	80	130	30	300
	Expected(fe)
Rating	A	B	C	F	Total
Excellent	10.00	13.33	21.67	5.00	50
average	30.00	40.00	65.00	15.00	150
poor	20.00	26.67	43.33	10.00	100
Total	60	80	130	30	300
	Chi square=(fo-fe)^2/fe
Rating	A	B	C	F	Total
Excellent	1.600	1.633	2.051	0.800	6.085
average	0.833	0.625	1.538	0.000	2.997
poor	0.050	0.004	0.256	0.400	0.711
Total	2.483	2.263	3.846	1.200	9.792

Test statistic:

Chi square=9.792

df=(3-1)*(4-1)=6

p-value=CHIDIST(9.792,6)=0.1337

As,p-value>0.05,we fail to reject the null hypothesis.

There is not sufficient evidence to conclude that teacher ratings are dependent on the grades.