Mode, median and ange模式，中位数和范围.pptVIP

Mode, Median and Range Aim: To find the mode, median and range, and the modal class for grouped data. Put these numbers in numerical order with the smallest first. 2, -3, 1, 4, -4, 0, 5, -2 Averages The Mode The mode is a type of average The mode is the value that occurs most often in a set of data Example What letter does your first name begin with? Mode, Median and Range Aim: To find the mode, median and range, and the modal class for grouped data. The Median The median is another type of average The median is the middle value for a set of data when the values are put in numerical order. The median The Range The range is not an average. The range of a set of data is the largest value minus the smallest value. It shows how the data is spread out. Find the range: The Range Modal Class Modal Class Extension * * 7, 3, 9, 2, 10, 8, 5, 4, 14, 12 2, 3, 4, 5, 7, 8, 9, 10, 12, 14, 34, 67, 38, 19, 44, 57, 24, 31, 62, 20 19, 20, 24, 31, 34, 38, 44, 57, 62, 67 -5 1 -4 -3 -2 0 2 4 5 -4 -3 -2 -1 0 2 3 4 5 1 An average is a useful statistic because it represents a whole set of values by just a single or typical value. Where have you heard the word average before? Where have you seen it used? 5, 6, 8, 2, 4, 5, 3, 5 MODE = 5 Sometimes there is no mode because either all the values are different, or no single value occurs more often than other values What is the mode first letter for a name in class 7Y2? THE MODE DOESN’T HAVE TO BE A NUMBER PAGE 52 EXERCISE 5A QUESTION 1 THE MODE Example 6, 8, 3, 7, 5, 2, 4 in order 2, 3, 4, 5, 6, 7, 8 Median = 5 For an odd number of values in data set, there is only one middle value. This is the median. What is the median test score for the following set of results? 5, 7, 7, 8, 10, 12, 14, 15 For an even number of values in a data set, there are two middle values. The median is the value in the middle of these two values. Median = 9 PAGE 51 EXERCISE 5A QUESTION 2 A small range shows that the values in a set of data are similar in size A