Exam 25: Supplement H Measuring Output Rates

An undergraduate business student studies diligently in the library during dead week in anticipation of an outstanding performance on her final exams. She asks a friend to spy on her at random intervals to determine what percentage of time she is actually studying. Over the course of three days, her friend records the following observations: If the student wants a 95 percent confidence level (z = 1.96) and a degree of precision of + 0.08, how many more observations are needed?

Table H.1 A worker was observed for four cycles in a repetitive task that contains four distinct elements. The observer recorded the following items in seconds, using the snap-back method: -The observer assigned a performance rating factor of 1.15 to the worker and the company employs an allowance factor of 20%. What is the standard time for Element 3?

Table H.3 A worker was observed for four cycles in a repetitive task. The observer recorded the following times, in seconds, using the continuous method. The ratings for each element and frequency it is performed are also indicated in the table. The allowance fraction is 20 percent. -Use the information in Table H.3. What is the normal time for the complete cycle?

The Dean's office is interested in determining the percentage of students receiving A's in their study tour classes. The results of three classes are summarized in this table: The Assistant Dean wants a 98 percent confidence level and a degree of precision of + 0.04. How many more observations are needed?

A manager wants to determine the proportion of time a cashier is idle. A work sampling method was used, and the idle time was found to be 20 percent based on 100 observations. If the manager wants a + 0.05 with a 95 percent confidence level (z = 1.96), how many MORE observations are needed?

A time study analyst has found the select time for a work element to be 14.0 minutes, with a sample standard deviation of 3.2 minutes. What is the minimum sample size needed if the estimate is to be within 4 percent of the average 95 percent of the time (z = 1.96)?

With the use of the elemental standard data approach:

An industrial engineer is conducting a time study for a work element. The select time is 4.5 minutes, and the sample standard deviation of the observed time is 20 seconds. What is the appropriate sample size if the estimate is to be 5 percent of the True average time 95 percent of the time?