In: Chemistry
Consider 25 ± 1 (n=5) and 26 ± 1 (n=6); The uncertainty listed is the standard deviation. Are these two measurements significantly different at the 95% confidence limit ?
25 ± 1 (n=5)
mean = x = 25
standard deviation = 1
n = 5
confidence interval = x + t.S/ sqrt(n)
= 25 + 2.776 x 1 / sqrt(5)
= 25 + 1.24
26 ± 1 (n=6)
n = 6
if n = 6 degrees of freedom = n-1 = 5 at 95% the t- value = 2.571
confidence interval = x + t.S/ sqrt(n)
= 26 + 2.571 x 1 / sqrt(6)
= 26 + 1.049
yes , these two measurements significantly different at the 95% confidence limit