Loading…
Loading…
SigmaCalc
The small-sample cousin of the z-score, used when you don't know the true population standard deviation.
Both measure how far a sample statistic is from an expected value in standard-error units. Use a t-score when your sample is small or you're estimating the population standard deviation from the sample itself, rather than knowing it exactly.
Compare your t-score's absolute value against a critical value from a t-distribution table for your degrees of freedom (n − 1) and chosen significance level — if it exceeds the critical value, the difference is statistically significant.
t-score
1.826
t = (x̄ − μ) ÷ (s ÷ √n)
What you entered
Standard error of the mean
15 ÷ √30= 2.7386t-score
(105 − 100) ÷ 2.7386= 1.8257Result
t-score: 1.826
A t-score of 1.826 tells you how many standard errors your sample mean is from the population mean — compare it to a t-table critical value for your degrees of freedom to test significance.