The null and alternative hypothesis would be: \[ \begin{array}{l} H_{0}: \mu=H_{0}: \mu=H_{0}: p=0.15 \quad H_{0}: p=0.15 \quad H_{0}: \mu=H_{0}: p=0.15 \\ H_{1}: \mu \neq H_{1}: \muH_{1}: p>0.15 \\ \end{array} \] The test is: left-tailed right-tailed two-tailed os Based on a sample of 115 men, $\frac{21}{115}$ of the men owned cats The test statistic is: $z=$ (to 2 decimals)

Step 1 ：Define the null and alternative hypothesis as follows: \[H_{0}: p=0.15\] \[H_{1}: p \neq 0.15\]

Step 2 ：Based on a sample of 115 men, calculate the sample proportion (\(\hat{p}\)) of men who own cats as \(\frac{21}{115}\)

Step 3 ：Calculate the test statistic for a hypothesis test for a proportion using the formula: \[z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}}\] where \(\hat{p}\) is the sample proportion, \(p_0\) is the hypothesized population proportion, and \(n\) is the sample size

Step 4 ：Substitute the values into the formula: \(\hat{p} = \frac{21}{115}\), \(p_0 = 0.15\), and \(n = 115\)

Step 5 ：Calculate the test statistic to get \(z = 0.98\) to two decimal places

Step 6 ：Final Answer: The test statistic is \(\boxed{0.98}\)