
MATLAB: An Introduction with Applications
6th Edition
ISBN: 9781119256830
Author: Amos Gilat
Publisher: John Wiley & Sons Inc
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Transcribed Image Text:Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 12.5 minutes. The standard deviation
of completion times was 1.2 minutes. An analyst at the company suspects that, under new management, the mean completion time, µ, is now less than 12.5
minutes. To test this claim, a random sample of 60 completion times under new management was taken by the analyst. The sample had a mean of 12.4
minutes. Can we support, at the 0.05 level of significance, the claim that the population mean completion time under new management is less than 12.5
minutes? Assume that the population standard deviation of completion times has not changed under new management.
Perform a one-tailed test. Then complete the parts below.
Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.)
(a) State the null hypothesis H and the alternative hypothesis H₁.
H₂₁:0
H₁ :0
(b) Determine the type of test statistic to use.
(Choose one)
(c) Find the value of the test statistic. (Round to three or more decimal places.)
0
(d) Find the p-value. (Round to three or more decimal places.)
(e) Can we support the claim that the population mean completion time under
new management is less than 12.5 minutes?
OYes No
μ
|X
0=0
O
X
S
OO
☐#0 0<0
р
020
0>0
Ś
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