I tried doing this question using the example shown in the lecture by but i could not get the answer. I calculated the actual total input which i got $ 1253.19 which i think is good. I calculated the standard total input at std mix for actual output and got $1273. To get to this number i multiplied 450g,150g,10g by the 950 units and converted them in kg to get 427.5 kg, 142.5kg,9.5 kg totaling 579.5 kg. i multiplied by the std cost per kg for each and therefore totaling to the number above.