6.11. Using the examples in section 6.7 as a model, write a function function [mu, sigma] gradestat (student,asgnt) that computes grade averages and standard deviations for a field named in the input argument asgnt. 6.11. Using the examples in section 6.7 as a model, write a function function [mu, sigma] gradestat (student,asgnt) that computes grade averages and standard deviations for a field named in the input argument asgnt