A textile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 ki
lograms with a standard deviation of 0.5 kilograms. The company wishes to test the hypothesis H0: µ = 12 against H1: µ < 12 using a random sample of n = 4 specimens. Calculate the P-value if the observed statistic is Xbar (average) = 11.25
Given that a textile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms.
H0: µ = 12 against H1: µ < 12
n =4
std error =
Mean difference
Test statistic t = mean diff/std error = -3
p value=0.00135 <0.05 our significance level
So reject H0
There is evidence to prove that mean is less than 12 kg.