2. A work sampling study is to be performed in the maintenance department of a manufacturing company. Preventive maintenance is one of the main activities performed by the workers, but not the only activity. The department involves 5 human workers, and the duration of the study is fifteen days. The workday is 7:30 am to 4 pm with lunch from 11:30 am to 12 pm and two 15 minutes breaks, one in the middle of the morning hours and the second in the middle of the afternoon hours. The supervisor of the department estimates that the proportion of time spent for preventive maintenance is 64% of each workers day. (a) Schedule 40 random observations in clock times in the proper chronological order using the Random numbers Table provided (last page). Starting at element 1 at the top of column number 5. (b) At the 95% confidence level, how many observations would be required if the lower and upper confidence limits are 0.60 and 0.68, respectively. (c) Regardless of your answer in the preceding part (b), a total of 800 random observations were actually taken during this 15 workdays, and workers were doing preventive maintenance in 540 of these observations. Construct a 97.5% confidence interval for the true proportion of time doing preventive maintenance. (d) As records for the 15 days of the study indicate that 540 preventive maintenance operations were completed. Estimate the average time for each one of these preventive maintenance operation? (e) Determine an approximation of the standard time for one preventive maintenance operation, given that an average performance rating for the worker was observed to be 90%, and the PFD allowance is 14%. 2. A work sampling study is to be performed in the maintenance department of a manufacturing company. Preventive maintenance is one of the main activities performed by the workers, but not the only activity. The department involves 5 human workers, and the duration of the study is fifteen days. The workday is 7:30 am to 4 pm with lunch from 11:30 am to 12 pm and two 15 minutes breaks, one in the middle of the morning hours and the second in the middle of the afternoon hours. The supervisor of the department estimates that the proportion of time spent for preventive maintenance is 64% of each workers day. (a) Schedule 40 random observations in clock times in the proper chronological order using the Random numbers Table provided (last page). Starting at element 1 at the top of column number 5. (b) At the 95% confidence level, how many observations would be required if the lower and upper confidence limits are 0.60 and 0.68, respectively. (c) Regardless of your answer in the preceding part (b), a total of 800 random observations were actually taken during this 15 workdays, and workers were doing preventive maintenance in 540 of these observations. Construct a 97.5% confidence interval for the true proportion of time doing preventive maintenance. (d) As records for the 15 days of the study indicate that 540 preventive maintenance operations were completed. Estimate the average time for each one of these preventive maintenance operation? (e) Determine an approximation of the standard time for one preventive maintenance operation, given that an average performance rating for the worker was observed to be 90%, and the PFD allowance is 14%