0.09的计数单位是____,它有____个这样的计数单位,0.50的计数单位是____。
—Guang'an is a beautiful city, isn't it?
—Yes. There are about two _______ visitors here every week.
质量指标
值分组
75,85)
85,95)
95,105)
105,115)
115,125
频数
6
26
38
22
8
则样本的该项质量指标值落在105,125上的频率为____.