I have a question about capital budgeting.

I am working on a problem in which I need to calculate the profitability index. The formula I have for this is profitability index = present value of cash inflows / investment required.

The present value of my cash inflows is $379,190. Th investment needed for the piece of equipment being purchased is $315,000. The problem also specifies that $60,000 will be needed in working capital. The working capital will be released after 6 years. The required rate of return is 14%.

I am wondering if the profitability index would be calculated as $379,190 / $315,000 or if I need to include the working capital in the denominator as well such as $379,190 / ($315,000 + $60,000).