谁帮我算下均数±标准差
第一组：年龄：21,22,27,28,16,16,15,16,16,15,16,17,17,12,10,16,4,15,19,16,61,4,14,14,9,5,2,9,4,55,14,38,11,3,3,10,32,22,22,33,23,27,21,15,5,38,37,6,22,31,35,52,25,14,20,17,14,14,16,52,5,35,16,15,32,28,15
第二组：天数：10,9,2,7,9,9,9,10,6,10,5,9,8,8,7,5,6,4,5,7,10,6,4,4,6,5,12,10,4,10,5,4,3,4,4,3,7,5,5,6,9,6,5,4,7,7,13,3,12,5,7,4,4,5,7,6,8,9,8,12,10,7,5,6,8,9,6
第三组：天数：51例,潜伏期第一天发病27,第二天10,第三天6,第四天7,第五天1,平均潜伏期多少天?
第四组：天数,65例样本,第一天转阴1例,第二天7,第三天30,第四天17,第五天6,第六天4,平均多少天转阴