Question

A UW instructor reads that 50% of the students who sit in the front of the classroom get A’s, compared to 30% of students who sit in the middle and 20% of students who sit in the back. The instructor recorded the preferred seating locations of his A students and found that 17 sat in the front of the room, 9 sat in the middle of the room, and 5 sat in the back of the room. Does this instructor’s class follow the distribution he read about?

Answer 1

Ans:

Chi square Goodness of fit:

Total number of observations=17+9+5=31

Expected count=p_i*31

	Observed(fo)	Expected(fe)	(fo-fe)^2/fe
Front	17	15.5	0.145
Middle	9	9.3	0.010
Back	5	6.2	0.232
Total	31	31	0.387

Test statistic:

Chi square score=0.387

df=3-1=2

p-value=CHIDIST(0.387,2)=0.8240

Assume significance level=0.05

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

Yes,We can conclude that this instructor’s class follow the distribution he read about.