Choose the confidence level
Find the sample size
Compute the degrees of freedom: df = n – 1
Find the critical t-value in the t-table using the degrees of freedom and confidence level
Calculate the sample mean
Calculate the sample standard deviation
Compute the standard error: s / √n
Compute the margin of error: t* × (s / √n)
Find the confidence interval: sample mean ± margin of error
Write the lower and upper bounds of the interval