Please include excel formulas so that I understand how to work the problem. thank you

The following data were obtained by observing a five-step job of a financial manager's assistant. 3 Observations (minutes/cycle) Performance Rating 4 Element (%) 1 2 3 4 5 5 A 95 1.40 1.42 1.39 1.36 1.41 3 B 115 2.10 2.05 2.00 1.85 1.76 7 C 105 1.60 1.35 1.50 1.45 1.55 3 D 95 1.82 1.74 1.70 1.63 1.63 3 F 100 2.01 2.10 1.90 1.85 1.76 0 1 a. Using the data and an allowance of 12 percent of job time, determine a standard time for the operation. 2 3 4 5 6 7 8 9 b. Determine the number of observations that would be required to estimate the mean time for element D within 3.5 0 percent of the true value with a confidence of 95 percent. -1 -2 -3 -4 -5 -6 27 -8 c. How many observations would be needed to estimate the mean time for element E to within 0.08 minutes of its 9 actual value with a confidence of 98 percent? -0 -1 2 3 -4 5 -6 7 8 9 *Round your final answers to two decimal places for part a. 0 *Round your final answers to zero decimal places for parts b&c