输入一个班学生大学计算机基础成绩记录显示所有成绩记录 计算并输出平均成绩,均方差输出成绩与排名结果存入文件输入一个班学生成绩记录显示所有成绩记录 计算并输出平均成绩,均方差输出成绩与排名结果存入文件-Enter a class of basic computer record of achievement to show all the track record　calculate and output the average score, standard deviation deposited in the track record of a class file input output results and ranking results show all the track record　calculate and output grade point average, standard deviation of outputscores and ranking results into a file