In: Statistics and Probability
Conduct the following test at the a=0.10 level of significance by determining
(a) the null and alternative hypotheses,
(b) the test statistic
(c) the critical value. Assume that the samples were obtained independently using simple random sampling.
Test whether p1≠p2. Sample data are x 1 = 28, n 1= 254, x 2 = 36, and n 2= 301
Solution:
a)
The null and alternative hypotheses are
H0 : = vs Ha :
b)
1 = x1 / n1 = 28/254 = 0.1102
2 = x2 / n2 = 36/301 = 0.1196
Let be the pooled proportion.
= (x1 +x2)/(n1 + n2) = (28+36)/(254+301) = 0.1153
1 - = 1 - 0.1153 = 0.8847
The test statistic z is
z =
= (0.1102 - 0.1196)/[0.1153*0.8847*((1/254)+(1/301))]
= -0.345
Test statistic z = -0.345
c)
= 0.10
/2 = 0.05
sign in Ha.
So , the test is TWO tailed.
So , critical values are
Critical values are -1.645 , 1.645
d)
Decision:
Fail to reject H0
(Because z = -0.345 is not in the rejection region.)
e)
Conclusion:
There is not sufficient evidence to support the claim that