What is the 975th percentile of a normal distribution with m
What is the 97.5th percentile of a normal distribution with mean = 10 and standard deviation = 4?
19.60
15.12
17.84
16.58
1 points
| a. | 19.60 | |
| b. | 15.12 | |
| c. | 17.84 | |
| d. | 16.58 | 
Solution
First, we get the z score from the given left tailed area. As          
           
 Left tailed area =    0.975      
           
 Then, using table or technology,          
           
 z =    1.959963985      
           
 As x = u + z * s,          
           
 where          
           
 u = mean =    10      
 z = the critical z score =    1.959963985      
 s = standard deviation =    4      
           
 Then          
           
 x = critical value =    17.83985594 = 17.84 [answer, c]      

