Grouped frequency distribution - Class Intervals and Frequency .

Grouped Frequency Distribution :

Here, we classify the data into different classes (or class intervals) by dividing the entire range of the values of the variable into suitable number of groups. And then we proceed finding the number of observations in each group.

If we divide the total range of values i.e MAX(scores)-MIN(scores) ,here 78-15 = 63 into group of size 5 each, then we will get =(63/5) = 13 groups.

So, formula for group is =ROUND((MAX(scores) - MIN(scores))/5,0) .

Next, we need to find the various groups into which the value of the variable are classified. i.e class intervals. The width or the magnitude of the classes is 5 here. And the total interval is 13 that we found above.

Here, we concatenate the lower and upper class limits of each group. For that formula used is:


{=MIN(scores)+5*ROW(INDIRECT("1:13"))-5 &"-"& MIN(scores)+5*ROW(INDIRECT("1:13"))-1}.

Finally, we are interested to know the number of students ( frequency) falling in each group. So here is the formula for it.

{=FREQUENCY(scores,MIN(scores)+5*ROW(INDIRECT("1:13"))-1)}

Note, Here Bins are Upper Limit (that we found above second part of concatenates) that are used for best results.