What is the appropriate sample size to estimate the time corresponding to element 2 within 10% of the true mean, with 95% confidence?

When conducting a time study of the Triple R Company's health insurance claims adjustment process, analyst Pablo Marmol applies the continuous method of time recording. The activity is divided into four work elements. Figure 7.3 shows the performance classification factors (RF) and the times recorded by the continuous method, r, for each work item. Process: processing for an insurance claim Date: 05/05/05 Observador: Pedro (Triple R Company) Pica Piedra Observaciones t RF Work item 1 21 45 1. Verify that the forms are tl 0.50 0.55 0.45 0.60 0.50 0.52 1.1 0.5070 completed and signed. 0.50 3.30 5.70 8.20 10.85 2. Write the amount of the claim, t 0.20 0.15 0.25 0.35 0.25 0.24 1.2 0.0742 review the computations. 0.70 3.45 5.95 8.55 11.10 3. Determine the proportion of t 0.75 0.60 0.55 0.70 0.65 0.65 0.0791 claims that would be denied. 1.45 4.05 6.50 9.25 11.75 4. 1.30 1.20 1.10 1.10 1.30 1.20 0.9 0.1000 Generate the letter form, enter the data for the check. 2.75 5.25 7.60 10.35 13.05 o 3 r r 1.2 r t r c. What is the appropriate sample size to estimate the time corresponding to element 2 within 10% of the true mean, with 95% confidence