Conduct a test at the alphaequals0.05 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 122​, n 1 equals 244​, x 2 equals 137​, and n 2 equals 311.

Respuesta :

Answer:

There is not enough evidence to reject the null hypothesis.

Step-by-step explanation:

(a)

The hypothesis can be defined as follows:  

H₀: p₁ - p₂ ≤ 0 vs. Hₐ: p₁ - p₂ > 0.  

(b)

The test statistic is defined as follows:

 [tex]z=\frac{\hat p_{1}-\hat p_{2}}{\sqrt{\hat P(1-\hat P)[\frac{1}{n_{1}}+\frac{1}{n_{2}}]}}[/tex]

The information provided is:

n₁ = 244

n₂ = 311

x₁ = 122

x₂ = 137

Compute the sample proportions and total proportions as follows:

[tex]\hat p_{1}=\frac{x_{1}}{n_{1}}=\frac{122}{244}=0.50\\\\\hat p_{2}=\frac{x_{2}}{n_{2}}=\frac{137}{311}=0.44\\\\\hat P=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{122+137}{244+311}=0.47[/tex]

Compute the test statistic value as follows:

 [tex]z=\frac{\hat p_{1}-\hat p_{2}}{\sqrt{\hat P(1-\hat P)[\frac{1}{n_{1}}+\frac{1}{n_{2}}]}}[/tex]

    [tex]=\frac{0.50-0.44}{\sqrt{0.47(1-0.47)[\frac{1}{244}+\frac{1}{311}]}}\\\\=1.41[/tex]

The test statistic value is 1.41.

The decision rule is:

The null hypothesis will be rejected if the p-value of the test is less than the significance level α = 0.05.

Compute the p-value as follows:

 [tex]p-value=P(Z>1.41)\\=1-P(Z<1.41)\\=1-0.92073\\=0.07927\\\approx 0.08[/tex]

*Use a z-table.

The p-value of the test is 0.08.

p-value = 0.08 > α = 0.05

The null hypothesis will not be rejected at 5% significance level.

Thus, there is not enough evidence to reject the null hypothesis.