In: Statistics and Probability
Conduct a test at the alphaequals0.01 level of significance by determining (a) the null and alternative hypotheses, (b) the test statistic, and (c) the P-value. Assume the samples were obtained independently from a large population using simple random sampling. Test whether p 1 greater than p 2. The sample data are x 1 equals 126, n 1 equals 241, x 2 equals 131, and n 2 equals 302. (a) Choose the correct null and alternative hypotheses below. A. Upper H 0 : p 1 equals p 2 versus Upper H 1 : p 1 not equals p 2 B. Upper H 0 : p 1 equals 0 versus Upper H 1 : p 1 not equals 0 C. Upper H 0 : p 1 equals p 2 versus Upper H 1 : p 1 greater than p 2 Your answer is correct.D. Upper H 0 : p 1 equals p 2 versus Upper H 1 : p 1 less than p 2 (b) Determine the test statistic. Need to know the P-Value as well and the result of this hypothesis
a)
p1 = p2
p1 > p2
b)
sample #1 ----->
first sample size, n1=
241
number of successes, sample 1 = x1=
126
proportion success of sample 1 , p̂1=
x1/n1= 0.5228
sample #2 ----->
second sample size, n2 =
302
number of successes, sample 2 = x2 =
131
proportion success of sample 1 , p̂ 2= x2/n2 =
0.4338
difference in sample proportions, p̂1 - p̂2 =
0.5228 - 0.4338 =
0.0890
pooled proportion , p = (x1+x2)/(n1+n2)=
0.4733
std error ,SE = =SQRT(p*(1-p)*(1/n1+
1/n2)= 0.0431
Z-statistic = (p̂1 - p̂2)/SE = ( 0.089
/ 0.0431 ) =
2.0648
C)
p-value = 0.0195
[excel function =NORMSDIST(-z)]
decision : p-value>α,Don't reject null hypothesis
There is not enough evidence to conclude that p 1 greater than p 2