A.是等距分组B.第一组假定下限是0C.相邻组限是重叠的D.分组标志为连续型变量E.某学生的成绩80分应归在70-80这一组
单项选择题以2000年a0为最初水平,2016年an为最末水平,计算钢产量的年平均发展速度时,须开()
A.15次方B.16次方C.17次方D.18次方
单项选择题如果居民按报告期价格购买商品需多支出40万元,报告期商品销售额为200万元,则价格指数为()
A.1.2B.0.8C.1.25D.0.83
单项选择题品合格率指标是()
A.比例相对指标B.结构相对指标C.比较相对指标D.强度相对指标
单项选择题某厂某年职工劳动生产率为20000元,是历史最高水平的1.2倍。这里的1.2倍是()
A.比例相对数B.计划完成相对数C.强度相对数D.动态相对数
单项选择题The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed. What is the approximate range of the number of phone calls arriving each hour?()
A.80 B.200 C.20 D.100
单项选择题The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed. What is the cumulative frequency of the third class?()
A.80 B.0.40 C.155 D.75
单项选择题A cumulative frequency distribution would provide().
A.a graph of a frequency distribution B.a running total of the frequencies in the classes C.the proportion of the total frequencies which fall into each class D.a very cloudy picture of the frequencies
单项选择题Which of the following is best to show the percentage of a total budget that is spent on each category of items?()
A.histogram B.ogive C.stem and leaf chart D.pie chart
单项选择题One rule that must always be followed in constructing frequency distributions is that ().
A.the number of classes must be less than 10 B.each data point can only fall into one class C.the width of each class is equal to the range D.the number of intervals must be an odd number
单项选择题One advantage of a stem and leaf plot over a frequency distribution is that ().
A.it contains more class intervals B.the values of the original data are retained C.the class midpoints are used as the stem D.the class midpoints are used as the leaf