SOLUTION: A sample of 200 observation from the first population indicated that X1 is 170. A sample of 150 observations from the second population revealed X2 to be 110. Use the 0.05 level to

Algebra ->  Probability-and-statistics -> SOLUTION: A sample of 200 observation from the first population indicated that X1 is 170. A sample of 150 observations from the second population revealed X2 to be 110. Use the 0.05 level to      Log On


   



Question 1118421: A sample of 200 observation from the first population indicated that X1 is 170. A sample of 150 observations from the second population revealed X2 to be 110. Use the 0.05 level to test the hypothesis
A) what is the decision rule
B)What is the pooled proportion
C)What is the test statistics
D)what is the decision regarding null hypothesis

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Ho is that the proportions are equal
Ha is that the proportions are not equal
alpha is 0.05 P{reject Ho|Ho true}
test stat is a 2 sample proportion test
critical value is |z|>1.96
pooled proportion is (pi*n1+p2*n2)/(n1+n2) or (170+110)/350=0.80; p1=0.85 and p2=0.733
test statistic is a z=(0.85-0.733)/SE
SE is sqrt (p*(1-p))((1/n1)+(1/n2))
=sqrt(.16*0.011667)
=0.0432
z=0.117/0.0432=2.71
reject Ho and conclude the proportions are different. (Another way to say it is that the two proportions would not be likely if they were taken from the same population.)