At a well-known business school the grade point averages (GPA) of its 1000 undergraduates are normally distributed with mean 2.84 and standard deviation 0.40.

(i) What percentage of the undergraduates have GPAs below 2.00 (i.e. "on probation")?

(ii) What GPA will be exceeded by only 20% of the student body?

(iii) Compute the lower and upper quartiles, and the interquartile range for this distribution.