Answer:
7.8
Step-by-step explanation:
Since the average is 7.8 and everyone scored the same score so
that means everyone scored a 7.8
 
        
             
        
        
        
The probability that at least two of the missiles hit the arsenal:
P ( x ≥ 2 ) = P ( x = 2 ) + P ( x = 3 )
P ( x = 2 ) = 0.75 · 0.85 · 0.1 + 0.85 · 0.9 · 0.25 + 0.75 · 0.9 · 0.15 =
= 0.06375 + 0.10125 + 0.19125 = 0.35625
P ( x = 3 ) = 0.75 · 0.85 · 0.9 = 0.57375
P ( x ≥ 2 ) = 0.35625 + 0.57375 = 0.93
Answer:
The probability is 0.93 or 93%. 
        
             
        
        
        
Answer:
Mixed Number Form:
-1   3/7
Step-by-step explanation: