Please help me find the payback period in years and the after-tax cash flows as well as the cumulative cash flows

Given the following attributes of an investment project with a ve-year life: investment outlay, year 0, $6,100; after-tax cash inflows, year 1, $850; year 2, $950; year 3, $2,000; year 4, $2,300; and year 5, $3,700. (a) Use the built-in NPV function of Excel to estimate the NPV of this project. Assume an after-tax discount rate of 8.0% (b) Estimate the payback period, in years, for this project under the assumption that cash inflows occur evenly throughout the year. (Round "Payback period" to the nearest whole number. Negative amounts should be entered with a minus sign. Round your answers to the nearest whole dollar amount.)