MIRR discount rate

Hello,

I have an exercise in which I need to calculate IRR & MIRR.
While calculating IRR I used 10% & 15% to end up with IRR of, let’s say 13%.

Which rate I should use to calculate MIRR with help of standard MIRR equation:

[PVR/PVI]*1/n*(1+r)-1

…and if it is IRR, I assume that I must calculate PV of inflows/outflows with that rate as well…correct?

Thank you in advance for your help!

Regards,
PJ