x is a normally distributed random variable with a mean of 8
x is a normally distributed random variable with a mean of 8 and a standard deviation of 1.5. find the value of x for which 70.54% of the area under the distribution curve lies to the right of it
 x is a normally distributed random variable with a mean of 8 and a standard deviation of 1.5. find the value of x for which 70.54% of the area under the distribution curve lies to the right of it
 x is a normally distributed random variable with a mean of 8 and a standard deviation of 1.5. find the value of x for which 70.54% of the area under the distribution curve lies to the right of it
Solution
First, we get the z score from the given left tailed area. As          
           
 Left tailed area = 1 - 0.7054 =   0.2946      
           
 Then, using table or technology,          
           
 z =    -0.539995697      
           
 As x = u + z * s,          
           
 where          
           
 u = mean =    8      
 z = the critical z score =    -0.539995697      
 s = standard deviation =    1.5      
           
 Then          
           
 x = critical value =    7.190006455   [ANSWER]  

