Answer:
42
Required probability:
- P(≤4) = (18 + 14 + 20 + 16)/(18 + 14 + 20 + 16 + 15 + 17) = 68/100 = 0.68
43
Required probability:
- P(>3) = (20 + 16 + 15 + 17) / (18 + 14 + 20 + 16 + 15 + 17) = 68/100 = 0.68
44
At least 2 students pass:
- P(2 or 3) = (3/5)² + (3/5)³ = 9/25 + 27/125 = 72/125 = 0.576
45
Number of x's:
- x/108 = 4/27
- x = 108*4/27
- x = 16