Answer:
The percentage that of people who gave the movie a rating between 6.8 and 8.8
P(6.8≤X≤8.8)  = 83.9≅ 84 percentage
Step-by-step explanation:
Step(i):-
Mean of the Population = 8.3 points
Standard deviation of the Population = 0.5 points
Let 'X' be the random variable in normal distribution
Let X = 6.8
[tex]Z = \frac{x-mean}{S.D} = \frac{6.8-8.3}{0.5} = -3[/tex]
Let X = 8.8
[tex]Z = \frac{x-mean}{S.D} = \frac{8.8-8.3}{0.5} = 1[/tex]
The probability that of people who gave the movie a rating between 6.8 and 8.8
P(6.8≤X≤8.8) = P(-3≤Z≤1)
           = P(Z≤1)- P(Z≤-3)
          =  0.5 + A(1) - ( 0.5 -A(-3))
          = A(1) + A(3)    (∵A(-3)=A(3)
         =  0.3413 +0.4986   (∵ From Normal table)
         = 0.8399
Conclusion:-
The percentage that of people who gave the movie a rating between 6.8 and 8.8
P(6.8≤X≤8.8)  = 83.9≅ 84 percentage