Questions: Some experts believe that 24% of all freshwater fish in a country have such high levels of mercury that they are dangerous to eat. Suppose a fish market has 250 fish tested, and 54 of them have dangerous levels of mercury. Test the hypothesis that this sample is not from a population with 24% dangerous fish, assuming that this is a random sample. Use a significance level of 0.05. Comment on your conclusion.
State the null and alternative hypotheses.
A. H0: P<0.24 Ha: P>0.24
B. H0: p=0.24 Ha: p>0.24
C. H0: p=0.24 Ha p ≠ 0.24
D. H0: p>0.24 Ha P<0.24
E. H0: p ≠ 0.24 H3: P=0.24
Transcript text: Some experts believe that $24 \%$ of all freshwater fish in a country have such high levels of mercury that they are dangerous to eat. Suppose a fish market has 250 fish tested, and 54 of them have dangerous levels of mercury. Test the hypothesis that this sample is not from a population with $24 \%$ dangerous fish, assuming that this is a random sample. Use a significance level of $0.05$. Comment on your conclusion.
State the null and alternative hypotheses.
A. $\mathrm{H}_{0} \cdot \mathrm{P}<0.24$
$\mathrm{H}_{\mathrm{a}}: \mathrm{P}>0.24$
B. $\mathrm{H}_{0}: \mathrm{p}=0.24$
$H_{\mathrm{a}}: p>0.24$
C. $H_{0} \cdot p=0.24$
$\mathrm{H}_{\mathrm{a}} \mathrm{p} \neq 0.24$
D. $H_{0}: p>0.24$
$\mathrm{H}_{\mathrm{a}} \mathbf{P}<0.24$
E. $H_{0}: p \neq 0.24$
$H_{3}: P=0.24$
Solution
Solution Steps
Step 1: State the Hypotheses
We are testing the following hypotheses:
Null Hypothesis: \( H_0: p = 0.24 \)
Alternative Hypothesis: \( H_a: p \neq 0.24 \)
Step 2: Calculate the Sample Proportion
The sample proportion of fish with dangerous levels of mercury is calculated as:
\[
\hat{p} = \frac{54}{250} = 0.2160
\]
Step 3: Calculate the Test Statistic
The test statistic \( Z \) is calculated using the formula:
\[
Z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1 - p_0)}{n}}}
\]
Substituting the values:
\[
Z = \frac{0.2160 - 0.24}{\sqrt{\frac{0.24(1 - 0.24)}{250}}} = -0.8885
\]
Step 4: Calculate the P-Value
The P-value associated with the test statistic \( Z = -0.8885 \) is:
\[
\text{P-value} = 0.3743
\]
Step 5: Determine the Critical Region
For a significance level of \( \alpha = 0.05 \) in a two-tailed test, the critical region is defined as:
\[
Z < -1.96 \quad \text{or} \quad Z > 1.96
\]
Step 6: Make a Decision
Since the calculated P-value \( 0.3743 \) is greater than \( \alpha = 0.05 \), we fail to reject the null hypothesis.
Final Answer
There is not enough evidence to say the sample is not from a population with \( 24\% \) dangerous fish. Thus, the answer is:
\[
\boxed{H_0 \text{ is not rejected}}
\]