Technology of production

The following schedule shows the technology of production at Mahalo Macadamia Nut Farm for 2015:

If macadamia nuts sell for $3.50 per pound and workers can be hired in a competitive labor market for $800 per week, how many workers should be hired? What if workers unionized and the weekly wages doubled? (Hint: Create marginal product and marginal revenue product columns for the table.) Explain your answers clearly.