Multiple-line waiting time at check-out cashiers at Albertson has standard deviation on 2.1

minutes. After converting to single waiting-line, a sample of 31 customers yields the standard deviation of 1.8 minutes. Test the claim, at 5% significant level, that the standard deviation of the waiting time in single-line method is less than the standard deviation of multiple-line method.

a.

State the claim statement in sentence.

b.

State the null and alternative hypothesis.

c.

Find the P-value. Determine whether reject or not reject null hypothesis.

d.

State the conclusion in sentence.