Data 1
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.) |
Number of observations | [removed] |