题干

人数相等的甲、乙两班学生参加了同一次数学测验,班级平均分和方差如下:平均分都为110,甲、乙两班方差分别为340、280,则成绩较为稳定的班级为(   )

A:甲班

B:乙班

C:两班成绩一样稳定

D:无法确定

上一题 下一题 0.0难度 选择题 更新时间:2017-02-19 01:50:49

答案(点此获取答案解析)

B

同类题1

Canada Day

                                                                  

                                                                                                                              

      Since 1982, July 1st has been officially known as Canada Day. Canadians of all ages take part in this festival across the country.
  Canada Day is the year's biggest national party. In many towns and cities, the government organizes a lot of events, often outdoors. These include parades(游行), concerts, festivals, firework displays and ceremonies for new Canadian citizens(公民). The celebrations often have a patriotic mood. Canada's national flag, a symbol for Canada Day, can be seen everywhere and a lot of people paint their faces red and white, which are Canada's national colors. The celebrations in Ottawa, Canada's capital city, are especially grand and exciting.
  In the province of Quebec, many home rentals(租赁)start on July 1st and last for exactly one year, and many people in Quebec spend Canada Day moving from one house to another. So in Quebec, Canada Day is also known as Moving Day.
  Many organizations, businesses and stores are closed this day. Only some bookstores, ho spitals and gas stations may be open. Post offices are closed, too. As Canada Day falls in the Canadian summer holiday period, all schools are closed as well. In some areas, special services are provided for large events. The concerts, parades and festivals may cause some traffic jams.