A recent report claimed that 13% of students typically walk to school. DeAnna thinks that the proportion is higher than 0.13 at her large elementary school. She surveys a random sample of 100 students and finds that 17 typically walk to school. DeAnna would like to carry out a test at the =0.05 significance level of
0: =0.13
:>0.13
where =the true proportion of all students at her elementary school who typically walk to school.
Calculate the standardized test statistic and the -value.
=1.19;-value = 0.8830
=1.19;-value = 0.2340
=−1.19;-value = 0.1170
=1.065;-value = 0.1435
=1.19;-value = 0.1170

Respuesta :

Step-by-step explanation:

To calculate the standardized test statistic and the p-value, we first need to compute the sample proportion (\( \hat{p} \)) and the standard error (\( SE \)):

\[ \hat{p} = \frac{x}{n} \]

\[ SE = \sqrt{\frac{p(1-p)}{n}} \]

Where:

- \( x \) is the number of students who typically walk to school in the sample (17)

- \( n \) is the sample size (100)

- \( p \) is the hypothesized proportion (0.13)

First, let's compute \( \hat{p} \):

\[ \hat{p} = \frac{17}{100} = 0.17 \]

Now, let's compute the standard error (\( SE \)):

\[ SE = \sqrt{\frac{0.13 \times (1-0.13)}{100}} \approx 0.0349 \]

Next, we calculate the z-score, which is the standardized test statistic:

\[ z = \frac{\hat{p} - p}{SE} = \frac{0.17 - 0.13}{0.0349} \approx 1.148 \]

Now, we need to find the p-value associated with this z-score. Since the alternative hypothesis is \( H_a: p > 0.13 \), we're interested in finding the probability that the proportion of students who walk to school is greater than 0.13. We'll use a standard normal distribution table or a calculator to find this probability.

Using a standard normal distribution table, the p-value corresponding to a z-score of 1.148 is approximately 0.1251.

Therefore, the correct answer is:

\[ z\text{-value} = 1.148; \text{p-value} \approx 0.1251 \]

None of the provided options exactly matches this calculation, but the closest one is:

\[ z\text{-value} = 1.19; \text{p-value} = 0.1170 \]

So, the closest option is:

\[ z\text{-value} = 1.19; \text{p-value} = 0.1170 \]