To solve this problem, we need to perform an ANOVA (Analysis of Variance) test to determine if there are any statistically significant differences between the means of the groups. The null hypothesis states that all group means are equal, while the alternative hypothesis states that at least one group mean is different. We will calculate the test statistic and the p-value to make a decision about the null hypothesis.
The problem provides several options for the null and alternative hypotheses. We need to select the correct pair for testing whether the mean drying times are the same.
- Null Hypothesis (\(H_0\)): The mean drying times for all groups are equal, i.e., \( \mu_1 = \mu_2 = \mu_3 = \mu_4 \).
- Alternative Hypothesis (\(H_a\)): Not all the population means are equal.
Thus, the correct hypotheses are:
\[
\begin{array}{c}
H_{0}: \mu_{1}=\mu_{2}=\mu_{3}=\mu_{4} \\
H_{a}: \text{Not all the population means are equal.}
\end{array}
\]
The problem states that the test statistic value is given as 2.51. This value is typically calculated using an ANOVA test when comparing more than two means.
The problem provides the \(p\)-value as 0.0970. This value is used to determine the statistical significance of the test statistic.
To make a conclusion, we compare the \(p\)-value to the significance level \(\alpha = 0.05\).
- If \(p\)-value \(\leq \alpha\), we reject the null hypothesis.
- If \(p\)-value \(> \alpha\), we do not reject the null hypothesis.
Given that the \(p\)-value is 0.0970, which is greater than 0.05, we do not reject the null hypothesis.
Hypotheses:
\[
\begin{array}{c}
H_{0}: \mu_{1}=\mu_{2}=\mu_{3}=\mu_{4} \\
H_{a}: \text{Not all the population means are equal.}
\end{array}
\]
Test Statistic: \(\boxed{2.51}\)
\(p\)-value: \(\boxed{0.0970}\)
Conclusion: Do not reject \(H_0\). There is not sufficient evidence to conclude that the mean drying times for the groups are different.