Question

The null and alternate hypotheses are:

H₀ : μ_d ≤ 0

H₁ : μ_d > 0

The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of four days last month.

	Day
	1	2	3	4
Day shift	11	12	14	18
Afternoon shift	9	10	13	16

At the 0.050 significance level, can we conclude there are more defects produced on the day shift? Hint: For the calculations, assume the day shift as the first sample.

a. State the decision rule.

b. Compute the value of the test statistic.

c. What is the p-value?

d. What is your decision regarding H₀?

Answer 1

a)

Decision rule :                   reject Ho if test statistic t>2.353

b)

  value of the test statistic t =7.000

c)

p value =0.0030

d)

reject Ho and conclude that there are more defects produced on the day shift