So class, today we are going to be learning about the measures of central tendancy.
And measures of spread.
The first central tendancy is Mean. For mean, you add up all the numbers, then divide by how many numbers there are. A way to remember is the mean teacher makes you add them all up then divide.
The second one is median. For median you have to put all the numbers from least to greatest then you cross one number from each end untill there is one left.
The third is mode. Mode is simple because mode occurs the most.
You use the mode when you wanna find the number that occur the most.
you use the median when you want to find the middle number of the data.
you use the mean when you want to find the average.
the next is mean absolute deviation. you find the mean, Then you compare each piece of data to the mean and list all differences. Last, you find the average of the list of differences.
The first measure of spread is range. With range, you subtract the lowest number from the highest.
you use the m.a.d. when you want to find the average of the average change.
you use the range like you would the mean.
The second measure of spread is inter quartile range. (IQR) You order the numbers from least to greatest. Then, you find the median number. Then you find the median of the lower half of data. Then you find the median of the upper half of the data. Then, you find the range of the upper and lower half.