Question

For a 99% confidence interval with a sample size of 10 What is the critical t-value?

Answer 1

This can be found using a t-table or a calculator. Using a t-table, with 9 degrees of freedom (n-1 = 10-1), the critical t-value for a two-tailed test at a 99% confidence level is approximately 3.250.

An example using python code:
import scipy.stats as stats

alpha = 0.01 # significance level
df = 9 # degrees of freedom
t_critical = stats.t.ppf(1 - alpha/2, df)
print(t_critical)

This gives a critical t-value of 3.2498, which is very close to the value obtained from the t-table.