In a population where the mean is \( \mu = 100 \) and the standard deviation is \( \sigma = 15 \), we are interested in finding the t-value for a 95% confidence level for a sample of size 25. What is the t-value?

Step 1 ：Step 1: Identify the degrees of freedom (df). The degrees of freedom is given by \( df = n - 1 \), where n is the sample size. So, \( df = 25 - 1 = 24 \).

Step 2 ：Step 2: Identify the desired confidence level. Here, the desired confidence level is 95%.

Step 3 ：Step 3: Look up the t-value that corresponds to the desired confidence level and the degrees of freedom in a t-distribution table. The t-value for a 95% confidence level and 24 degrees of freedom is approximately 2.064.