Question 389816
I will assume that YOU invested $1500 AT THE BEGINNING of the month of March, and that at the END of December, YOUR stock portfolio has worth $5200.  So that's after 10 months.  YOUR portfolio's monthly rate of change r is then computed as follows:
{{{5200 = 1500(1 +r)^10}}}
==> {{{r  = root(10, 5200/1500) - 1 = 0.1324}}}, to 4 decimal places.
That is 13.24% per month.