One of the greatest disadvantages of using range as a method of dispersion is that range is sensitive to outliers in the data. Range only considers the smallest and largest data elements in the set.
Know MoreIf outliers exist in a set of data such that the lowest or highest extremes are far away from almost every other data element in the set, then range may not be the best way to measure dispersion. For example, if one were to measure a student's consistency on quizzes, and he scored {40, 90, 91, 93, 95, 100} on six different quizzes, the range would be 60 points, marking considerable inconsistency. However, five of the six quizzes show consistency in the student's performance, achieving within 10 points of each other on all of these.
Using other methods of dispersion, such as measuring the interquartile range, the difference between the 25th and 75th percentile, provide a better representation of dispersion in cases where outliers are involved. Standard deviation and average deviation are also commonly used methods to determine the dispersion of data.
Learn more about StatisticsDiscrete data refers to data that has values that are different and separable from one another. This form of data typically represents items that can be counted. Some examples of discrete data include eye color and the number of pushups that someone can perform. This form of data is one of three main data types, along with continuous and categorical data.
Full Answer >Statistics is the study of numerical information, which is called data. People use statistics as tools to understand information. Learning to understand statistics helps a person react intelligently to statistical claims. Statistics are used in the fields of business, math, economics, accounting, banking, government, astronomy, and the natural and social sciences.
Full Answer >The main steps utilized in a statistical investigation include four components: clarifying the problem and formulating questions or hypotheses that can be answered with the data, designing or creating an appropriate experiment that can collect the data required, finding and using the appropriate techniques needed to accurately analyze the collected data, and interpreting the collected data and results so as to answer the questions and hypotheses that were proposed in the first place. The main steps in a statistical investigation are thought to be a cylindrical process that helps ensure that all procedures are completed logically. The aim of opening a statistical investigation is to answer the many questions that are present in the world, and is a technique that has been commonly applied by statisticians.
Full Answer >Some of the methods by which data can be collected for a statistical study are interviews, questionnaires, focus groups, field studies, direct observation, surveys, testing and experimenting. Depending on the nature of the study, the data-collection method can be based on either primary or secondary sources or a combination of both. Primary-source data collection refers to that which is obtained directly by the team conducting the study, while secondary-source data collection is obtained through a third-party source or data base such as a government census, research compilation or from organizational records.
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