1. The average score of statistics class was 71 with a standard deviation of 10 a. What is the z score of a student with a grade of 68? . Using the formula Z = ( X-M)/ SD Z= 68-71/ 10 = -.3 b. What is the z score of a student with a grade of 80? Using the formula Z= (X-M)/ SD Z= ( 80-71) / 10= .9 2. Using the same data in #1 answer the following: a. Approximately 68% (one standard deviation) of the score are between ____ and ____