I need help :)What’s m

Ben bowled 124 and 188 in his first two games. what must he bowl in his third game to have an average of at least 160?

Which is the standard form for this number? (4 x 1 100 ) + (8 x 1 1,000 ) + ( 3 x 1 100,000 ) ? a) 0.004803 b) 0.04803 c) 0.0483 d) 0.483

How do you solve a question like this?