PLEASE SHOW CALCULATIONS

The child is 41 and his mom, whose account he has inherited, was 72 when she passed away in January. The deceased parent had not taken any distributions out of the account for the year in which she passed away, although she had taken her RMD in the year before she passed. The total account balance on the previous December 31^st was $437,594. This client will inherit 25% of their deceased parents IRA which is now valued at $441,488. Assuming that the account is re-registered into the childs name in March, what is the relevant required minimum distribution and when must it be taken?