Question

there are 650, of that 650 48% do go, 44% doesn't go, how many students are not sure they will attend?

Answer 1

100% - (48% + 44%) = 100% - 92% = 8%

rule of three :

650 --- 100%
  x   ---- 8%

100x = 650 . 8
100x = 5200
x = 5200/100
x = 52

R : 52 (8%)

Answer 2

44% + 48% = 92%
48% go, 44% dont go...so thats 92% that either go or dont go....leaving u with 8% unsure 
0.08(650) = 52 are not sure they will attend