Please help with parts A, B and C. ASAP. Thank you!

The data in the table below represent time study observations for a woodworking operation. (Hint See Solved Problems section.) Click here for the Excel Data File -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.) 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.) c. How many observations would be needed to estimate the mean time for element 2 within 0.01 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.)