Chi square test

Question

for each of the following questions state the null and hypothesis

sketch the critical region indicating the critical value

calculate the test statistic and show where the test statistic falls on the sketch

make your decision and answer the question posed in problem.

 

after midterm, a random sample of 284 students were asked to evaluate teacher performance. the students were also asked to provide their midterm grade. only students with passing grades of an A, B, C, were included in the contingency table. use 5% level of significance to test the claim that teacher evaluations are independent of midterm grades

 

 

the national age distributions for college students are given as in the chart below. the western association of mountain colleges took a random sample of 212 students and obtained the sample of distribution in the second chart. does the given sample distribution fit the national distribution? use 5% level of significance.

 

Answer 1

284 students

N=284

alpha = 5% = .05

degrees of freedom = (r-1)(c-1) = (3-1)(3-1) = 2(2) =4

if evaluations are good, ok, and poor, 3 categories

calculate fe

then calculate X^2 = sum of (fo-fe)^2/fe

then look it up on a chi square table to find the area under the curve

reject Ho of fail to reject depending on the the table value compared to the critical value