Mean, Median, and Mode

  We have recently discussed mean, median, and mode.  Based on the notes I took in class, mean is the average of a group of given numbers.  First, you would add each of the numbers together.  You then take the sum and divide it by the amount of numbers you were given originally.  For example, 1,2,2,3,4,4,4,5.  Add 1+2+2+3+4+4+4+5. This equals 25.  Take your sum (25) and divide by 8 (amount of digits show).  The mean (average) is 3.125 or if you decide to round 3.13.   Median is said to be the "middle" number.  We already know 8 digits exist.  Being that there is an even number of digits we will have to take two digits from the center. 3 and 4.  Since there isn't a number exactly in the middle, you need to add 3 and 4 and divide by 2.  3+4=7.  Then 7 divided by 2 is 3.5.  Your median for the following numbers 1,2,2,3,4,4,4,7 is 3.5.  Mode is the number of times a number appears.  In this case, in the example above, the mode will be 4. By looking at 1,2,2,3,4,4,4,7 you can see 4 occurs three times.  

     I find this topic one of the easier ones in math.  I have seen it multiple times and I realize the importance of it now.  You can apply this to your classroom to find where your students scores stand.  Another part of this chapter I found interesting was standard deviation.  When the term was mentioned I didn't really remember what it was.  I found a simple explanation of what standard deviation is on Wikipedia.  I know Wikipedia isn't the best source but after reading some of the text it was similar to what was discussed in class.  

Standard deviation is a widely used measurement of variability or diversity used in statistics and probability theory. It shows how much variation or 'dispersion' there is from the 'average' (mean, or expected/budgeted value). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data is spread out over a large range of values.

As you can see, it is exactly what was discussed in class and I wanted to provide the few graphs we saw as well.  

Each graph above should look familiar.  As a teacher, you would want your students to be on the same "page".  This is why, standard deviation plays a major role and can help a teacher discover where her students stand.