Problem 7-10
| The data in the table below represent time study observations for a woodworking operation. (Hint: See Solved Problems section.) |
| OBSERVATIONS (minutes per cycle) | |||||||
| Element | Performance Rating |
1 | 2 | 3 | 4 | 5 | 6 |
| 1 | 110% | 1.20 | 1.17 | 1.16 | 1.22 | 1.24 | 1.15 |
| 2 | 115 | 0.83 | 0.87 | 0.78 | 0.82 | 0.85 | 1.32* |
| 3 | 105 | 0.58 | 0.53 | 0.52 | 0.59 | 0.60 | 0.54 |
|
|
|||||||
| *Unusual delay, disregard time. |
| a. | Based on the observations, determine the standard time for the operation, assuming an allowance of 15 percent of job time. (Round your intermediate calculations and final answers to 3 decimal places.) |
| Element | Standard time |
| 1 | [removed] |
| 2 | [removed] |
| 3 | [removed] |
|
|
|
| b. | How many observations would be needed to estimate the mean time for element 2 within 1 percent of its true value with a 95.5 percent confidence? (Round your intermediate calculations to 3 decimal places and round up your final answer to the next whole number.) |
| Number of observations | [removed] |
| c. | How many observations would be needed to estimate the mean time for element 2 within .01 minute of its true value with a 95.5 percent confidence? (Round your intermediate calculations to 3 decimal places and round up your final answer to the next whole number.) |
