Question

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the night shift than on the day shift. The mean number of units produced by a sample of 52 day-shift workers was 355. The mean number of units produced by a sample of 58 night-shift workers was 363. Assume the population standard deviation of the number of units produced on the day shift is 21 and 29 on the night shift.

At the 0.05 significance level, is the number of units produced on the night shift larger?

1. Is this a one-tailed or a two-tailed test?

• One-tailed test

• Two-tailed test

2. State the decision rule. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.)

3. Compute the value of the test statistic. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.)

4. What is your decision regarding H₀?

• Do not reject H₀.

• Reject H₀.

Answer 1

Claim: The number of units produced on the night shift larger.

The null and alternative hypothesis is

: Population mean for day shift

: Population mean for night shift.

a) One-tailed test

b) Level of singificance = 0.05

Critical value = 1.64

Decision rule: Test statistic > 1.64 we reject null hypothesis.

c)

n1 = 52

= 355

= 21

n2 = 58

= 363

= 29

Test statistic is

d)

Test statistic | z | > critical value we reject null hypothesis.

Reject H0