Average Rate of Return, Cash Payback Period, Net Present Value Method for a Service Company is 15%. \begin{tabular}{cccccc} \multicolumn{5}{c}{ Present Value of an Annuity of $1 at Compound Interest } \\ \hline Year & 6% & 10% & 12% & 15% & 20% \\ \hline 1 & 0.943 & 0.909 & 0.893 & 0.870 & 0.833 \\ 2 & 1.833 & 1.736 & 1.690 & 1.626 & 1.528 \\ 3 & 2.673 & 2.487 & 2.402 & 2.283 & 2.106 \\ 4 & 3.465 & 3.170 & 3.037 & 2.855 & 2.589 \\ 5 & 4.212 & 3.791 & 3.605 & 3.353 & 2.991 \\ 6 & 4.917 & 4.355 & 4.111 & 3.785 & 3.326 \\ 7 & 5.582 & 4.868 & 4.564 & 4.160 & 3.605 \\ 8 & 6.210 & 5.335 & 4.968 & 4.487 & 3.837 \\ 9 & 6.802 & 5.759 & 5.328 & 4.772 & 4.031 \\ 10 & 7.360 & 6.145 & 5.650 & 5.019 & 4.192 \\ \hline \end{tabular} Compute the following: a. The average rate of return, giving effect to straight-line depreciation on the investment. If required, round your answer to one decimal place. % b. The cash payback period. 4 years