One advantage of a stem and leaf plot over a frequency distribution is that （）.

某企业2018年技术工占50%，2019年新招收了一批学徒工，使学徒工的比重增加了10%。假定全厂各级工资水平均无变化，则2019年职工总平均工资将（）

A summary measure that is computed from a sample to describe a characteristic of the population is called（）

A student achieves an 82 on the first test in a statistics course. From this, she assumes that her average at the end of the semester (after other tests) will be about 82. This is an example of （）.

If the individual class frequency is divided by the total frequency, the result is the （）.

A politician who is running for the office of premier in a state with 3 million registered voters commissions a survey. In the survey, 53.6% of the 5000 registered voters interviewed say they plan to vote for him. The population of interest is the（）

对全国各铁路交通枢纽的货运量、货物种类等进行调查，以了解全国铁路货运概况。这种调查属于（）

Which of the following is best to show the percentage of a total budget that is spent on each category of items？（）

对某班级学生的生活状况进行统计调查，下列标志中属于不变标志的是（）

One rule that must always be followed in constructing frequency distributions is that （）.