It is equivalent too 5.3 and 5.30
        
             
        
        
        
Answer:
The probability there will be between 280 and 360 column inches of classified advertisement
P(280≤X≤360) = P(-2≤Z≤2) = 0.9544
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Given that the mean  the population = 320
The standard deviation of the Population = 20
Let 'X' be the random variable in a normal distribution
Let 'X' = 280

Let 'X' = 360

<u><em>Step(iii):-</em></u>
The probability there will be between 280 and 360 column inches of classified advertisement
P(280≤X≤360) = P(-2≤Z≤2)
                         = P(z≤2) -P(z≤-2)
                        = P(z≤2)+P(z≤2)
                       = 2P(z≤2)
                      = 2×0.4772     ( from normal table)
                     = 0.9544
 
        
             
        
        
        
Answer: s = -3.3
<u>Step-by-step explanation:</u>

                 -3.3 = s
 
        
             
        
        
        
Answer:
c
Step-by-step explanation: