Respuesta :
Answer:
The value of the standardized test statistic for this significance test is -1.25.
Step-by-step explanation:
We are given that in a recent poll, 30 percent of adults said they wanted to "cut down or be free of gluten".
The researcher conducts a survey of a random sample of 25 students at her university and five of them say they want to at least reduce gluten.
Let p = population proportion of students wanting to reduce gluten at the university.
So, Null Hypothesis, [tex]H_0[/tex] : p = 30% {means that the proportion wanting to reduce gluten at the university is the same as for all adults}
Alternate Hypothesis, [tex]H_A[/tex] : p < 30% {means that a smaller proportion of students would say they want to reduce or be free of gluten}
The test statistics that would be used here One-sample z test for proportions;
T.S. = [tex]\frac{\hat p-p}{\sqrt\frac{\hat p(1-\hat p)}{n} {} }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of students who would say they want to reduce or be free of gluten = [tex]\frac{5}{25}[/tex] = 0.20
n = sample of students taken = 25
So, the test statistics = [tex]\frac{0.20-0.30}{\sqrt\frac{0.20(1-0.20)}{25} {} }[/tex]
= -1.25
The value of standardized z test statistic is -1.25.
Using the z-distribution, it is found that the value of the standardized test statistic for this significance test is:
D) –1.091
At the null hypothesis, we test if the proportion is of 0.3, that is:
[tex]H_0: p = 0.3[/tex]
At the alternative hypothesis, we test if the proportion is of less than 0.3, that is:
[tex]H_1: p < 0.3[/tex]
The test statistic is given by:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
In which:
- [tex]\overline{p}[/tex] is the sample proportion.
- p is the proportion tested at the null hypothesis.
- n is the sample size.
For this problem, the parameters are:
[tex]p = 0.3, n = 25, \overline{p} = \frac{5}{25} = 0.2[/tex]
Hence, the value of the test statistic is:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
[tex]z = \frac{0.2 - 0.3}{\sqrt{\frac{0.3(0.7)}{25}}}[/tex]
[tex]z = -1.091[/tex]
A similar problem is given at https://brainly.com/question/24166849
