How Many Cycles Should Be Used in a Time Study

question 24

Multiple Choice

How many cycles should be used in a time study in order to be 98% confident that the time-study average job cycle time is within 4% of the true average job cycle time? Assume that the average job cycle time is 4.25 minutes and the standard deviation of the sample is 0.65 minutes.

• A)55 cycles
• B)70 cycles
• C)80 cycles
• D)95 cycles

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Definitions:

Planning Fallacy

The tendency to underestimate the time, costs, and risks of future actions while overestimating the benefits, leading to poor planning and time management.

Underestimating

The act of judging something to be of lower quantity, value, or importance than it actually is.

Project

A planned set of interrelated tasks to be executed over a fixed period and within certain costs and other limitations.

Overconfidence

A cognitive bias where an individual's subjective confidence in their judgments and abilities is greater than their objective accuracy.