The scores for all high school seniors taking the verbal section of the Scholastic Aptitude Test (SAT) in a particular year had a mean of 490 and a standard deviation of 100. The distribution of SAT scores is bell-shaped. What percentage of seniors scored between 390 and 590 on this SAT test?

The value is      

Step-by-step explanation:

From the question we are told that

   The mean is  

    The standard deviation is  

Generally the proportion of seniors scored between 390 and 590 on this SAT test is mathematically represented as

=>  

From the z table  the area under the normal curve to the left corresponding to  1 and  -1  is  

and

=>

Generally the percentage of seniors scored between 390 and 590 on this SAT test is mathematically represented as

=>    

=>