Question

Given a large range of numbers how can I determine the class intervals to use and if I need an equal or unequal class width histogram? Thanks! Please show some example. Really struggling with how can I know when do I need which of the two.

Answer 1

Firstly what we have to do with the data set of histogram is , find the minimum value for histogram, maximum value for histogram and interval count (max 100)

Next find the interval width from the findings of minimum , maximum and interval count

This is the easiest way to fix the class width for the histogram. Let me explain in detail

Interval width = (MAximum - Minimum)/Interval count

In the above example Refer F3 cell value conatins MAx value.

Maximum formula is "=MAX(B2:B51)"

Minimum formula is "=MIN(B2:B51)"

Interval count is 15. that you can fix based on the data set.

you an interval count is 5,10,15,20 and more than that according to the data volume

Interval width

formula is "=(F3-F4)/F5"

it is nothing but =(max-mim)/interval count

now we can align the the division and class interval with the above data.

since we fix the interval count as 15, so we have d-id upto 15

division

first value should be minimum value

from next value onwards add first value (inimum) + interval count .

drag the formula till the end.

next round up the value

now so easy to fix the class interval

take the rounded value to fix the interval.