The mode is the value that occurs the “modst”.Ĭentrality does not tell us everything we need to know about a data distribution. The thresholds for 1-day, 1-yr rainfall events range from 3.5 mm in the Northwest China to about 200 mm along the southeast coast ().The ratio of maximum to minimum threshold in China is much larger than that in Australia (160 mm/25 mm, Fu et al., 2010) and USA (100 mm/15 mm, Kunkel et al., 1999). I use the word “modst” to help students remember. If one value occurs the most, we call that value the mode if two values occur the most, then we can say the data is bimodal. The mode is the value that occurs the most.
Mode: This measure has its uses but is a little different from the other two. The median is the middle score of a set of data when the data is written in ascending order.ģ. The median in a roadway is in the middle of the road. Median: I use the median in a roadway to help me remember this one. We have all averaged a set of exam grades before. The mean is simply the average value of a data set.
Mean: This is most common used measure of central tendency. Measures of centrality approximate the center of a data distribution.ġ. In this section we will first discuss the centrality (or central tendency) of a set of data. Degree of freedom (df) It tells us the number of independent variables used for calculating the estimate between 2 sample groups.Eq-2 where, df degree of freedom n S size of the sample S Suppose, we have 2 samples A and B. *For sample mean we use an x with a bar over it, kind of like this: ¯ but I could not insert the symbol, so many times I just say “mean”.īelow are some less common statistics that one might use with a population or a sample. Mean (x*) Variance (s 2 ) Standard Deviation (s) Below are some common sample statistics and their abbreviations. A good sample is one that is proportionally equivalent to the population. Polls are generally based on a sample taken from the larger population. Sample Statistics are generated from collected measurements or data from a small portion of the population. Mean (µ) Variance (σ 2 ) Standard Deviation (σ) Below are some common population statistics and their abbreviations. If we know the actual population statistics, there is no need for a sample. Population Statistics are generally what we are trying to project or estimate. A statistic from a sample may infer certain information about the population. What Is A Statistic? A statistic is a measurement that we use in analyzing data. Statistics goes hand in hand with probability and the two topics are closely related. You may be required to take a course that gives a more in depth study later. This module will give you the basic concepts of statistics.