2.3.1频率直方图 例1：某工厂生产一种零件，由于生产过程中各 种随机因素的影响，零件长度不尽相同。现测 得该厂生产的100个零件长度（单位：mm)如下： 129,132,136,145,140,145,147,142,138,144,147,142,137,144,144, 134,149,142,137,137,155,128,143,144,148,139,143,142,135,142, 148,137,142,144,141,149,132,134,145,132,140,142,130,145,148, 143,148,135,136,152,141,146,138,131,138,136,144,142,142,137, 141,134,142,133,153,143,145,140,137,142,150,141,139,139,150, 139,137,139,140,143,149,136,142,134,146,145,130,136,140,134, 142,142,135,131,136,139,137,144,141,136. 这100个数据中，最小值是128，最大值是155。例1：某工厂生产一种零件，由于生产过程中各 种随机因素的影响，零件长度不尽相同。现测 得该厂生产的100个零件长度(单位: mm)如下: 2.3.1 频率直方图 129, 132, 136, 145, 140, 145, 147, 142, 138, 144, 147, 142, 137, 144, 144, 134, 149, 142, 137, 137, 155, 128, 143, 144, 148, 139, 143, 142, 135, 142, 148, 137, 142, 144, 141, 149, 132, 134, 145, 132, 140, 142, 130, 145, 148, 143, 148, 135, 136, 152, 141, 146, 138, 131, 138, 136, 144, 142, 142, 137, 141, 134, 142, 133, 153, 143, 145, 140, 137, 142, 150, 141, 139, 139, 150, 139, 137, 139, 140, 143, 149, 136, 142, 134, 146, 145, 130, 136, 140, 134, 142, 142, 135, 131, 136, 139, 137, 144, 141, 136. 这100个数据中，最小值是128，最大值是155。 155 128