An army depot that overhauls ground mobile radar systems is interested in improving its processes.One problem involves troubleshooting a particular component that has a high
Failure rate after it has been repaired and reinstalled in the system.The shop floor supervisor
Believes that having standard work procedures in place will reduce the time required for
Troubleshooting this component.Time (in minutes) required troubleshooting this component
Without and with the standard work procedure is recorded for a sample of 19 employees.In
Order to determine if having a standard work procedure in place reduces troubleshooting
Time, they should use
A)a test of two proportions.
B)a two-tailed test of two independent means.
C)a one-tailed test of two independent means.
D)a two-tailed paired t-test.
E)a one-tailed paired t-test.

Question

Quizplus · Accepted Answer

The scenario involves comparing the troubleshooting times for the same group of employees before and after implementing a standard work procedure. This comparison of two related samples (the same employees' performance before and after the change) suggests the use of a paired t-test. Since the hypothesis specifically concerns a reduction in time, a one-tailed test is appropriate, as it tests for a direction of change (decrease in troubleshooting time) rather than any change.

An Army Depot That Overhauls Ground Mobile Radar Systems Is