The width of class intervals is normally determined by the data and not whether you want to calculate the arithmetic mean.
For general population statistics you might use class widths of 6 or 10 years.
But if you were studying school children in the UK you might use the following, unequal bands:
Nursery-reception: 2 years
Years 1 and 2: 2 years
Years 3 to 6: 4 years
Years 7 to 9: 3 years (Lower secondary)
Years 10 to 11: 2 years (Upper secondary)
Years 12 to 13: 2 years (A levels).
they come in all sizes
Class width, from statistics, is the difference between the two boundaries of a class. A class is an interval that includes all of the values in a (quantitative) data set that fall within two numbers, the lower and upper limits of the class. Finally, a class boundary is the midpoint of the upper limit of one class and the lower limit of the next class.
It doesn't matter, the results are the same. A very basic law of arithmetic is: a times b = b times a So, in regard to the calculatuion of area, it DOES NOT MATTER .
It need not be, and often is not.
basically this is an exampleAGE (YEARS) FREQUENCY FREQUENCY DENSITYFD= Frequency DensityAge : 0
NONE
class width is a width width is a width nothing as class width is a width dont be confuse
try sqrt(N) where N represents the number of observations you have...
If you are choosing class intervals in preparation for making a histogram, and if you know that the data all fall in the range from zero through 60 then you could choose the intervals: 0 through 10 inclusive more than 10 to 20 inclusive move than 20 to 30 inclusive ... more than 50 to 60 inclusive
If the intervals are of different width, then it is a histogram.
First, you decide how many intervals you need. (Can be between 5-15). Then, you find the range (Max-Min=Range) Next you divide the range by the amount of intervals you wanted. The quotient is the width of your data Example: Intervals(Width=10 and Minimum=28)(When you add the width to the minimum, you should count the minimum too. Instead of 28+10=38, it would be 37 since the 28 count, and to check the answer you have to add ten going down) 28-37 38-47 48-57 58-67 68-77
Circ. = pi x diam./width Thus, 44 = 3.14 x width and width = 44 / 3.14 You do the arithmetic.
There is no correlation between class width and student achievement. Class width is arbitrary (there are rules of thumb for class width, and it depends on the range of the data).
Sometimes you do, sometimes you don't. It depends on the context.
Histogram
Width - about the width of a ladder Length - however long you want cleats spaced at intervals of between 30 to 40 cm
20-15=5