Find the critical value \( z_{\alpha / 2} \) that corresponds to the given confidence level. \( z_{\alpha / 2}=\square \) (Round to two decimal places as needed.)

To find the critical value \( z_{\alpha / 2} \), you need to know the confidence level you are working with. For instance, a 95% confidence level means that \( \alpha \) is 0.05, making \( \alpha / 2 = 0.025 \). You would then look up \( z_{0.025} \) in a standard normal distribution table, which gives you approximately 1.96. Rounding to two decimal places, for a 95% confidence level, \( z_{\alpha / 2} = 1.96 \). For a 99% confidence level, \( \alpha \) is 0.01, leading to \( \alpha / 2 = 0.005 \). The critical value \( z_{0.005} \) is approximately 2.576. Again, rounded to two decimal places, \( z_{\alpha / 2} = 2.58 \). Always check the precise value based on your specific confidence level!