Step 1 :Define the given values: \(n_1 = 1208\), \(n_2 = 1096\), \(\hat{p}_1 = \frac{186}{1208} = 0.154\), \(\hat{p}_2 = \frac{142}{1096} = 0.130\), and \(Z_{\alpha/2} = 2.576\) for a 99% confidence level.
Step 2 :Calculate the standard error (SE) using the formula \(SE = \sqrt{\frac{\hat{p}_1(1-\hat{p}_1)}{n_1} + \frac{\hat{p}_2(1-\hat{p}_2)}{n_2}}\). Substituting the given values, we get \(SE = 0.015\).
Step 3 :Calculate the confidence interval (CI) using the formula \(CI = \hat{p}_1 - \hat{p}_2 \pm Z_{\alpha/2} \times SE\). Substituting the given values, we get \(CI = 0.154 - 0.130 \pm 2.576 \times 0.015\).
Step 4 :Solve the above equation to get the lower and upper bounds of the confidence interval. The lower bound is -0.013 and the upper bound is 0.062.
Step 5 :Interpret the confidence interval: The 99% confidence interval for the difference between the proportion of males that have at least one tattoo and the proportion of females that have at least one tattoo is \([-0.013, 0.062]\). This means that we are 99% confident that the true difference in proportions lies within this interval. Since the interval contains 0, we cannot conclude that there is a significant difference between the proportions of males and females that have at least one tattoo.
Step 6 :\(\boxed{\text{Final Answer: The lower bound is -0.013 and the upper bound is 0.062.}}\)