<img src="https://static.zxtiku.com/wangke/imgs/topic/46df1ca0b01030f1fc4aa7e80de13ca3.png"/>、<img src="https://static.zxtiku.com/wangke/imgs/topic/a3a2a9c3ecbeed87d84b395976cd235c.png"/>、...、<img src="https://static.zxtiku.com/wangke/imgs/topic/4af07daa09a6e8af71b1a3cf2828e4eb.png"/>是来自总体<img src="https://static.zxtiku.com/wangke/imgs/topic/94802758083391a62425838bf176cd27.png"/>的一组简单随机样本，<img src="https://static.zxtiku.com/wangke/imgs/topic/6bd72106a57550f3c6cdc85c573db190.png"/>是样本均值。以下说法正确的是：