in statistics, what is the difference between class width and class interval? how do you compute them?

Question

please provide an example. thanks!

Answer 1

Let us look at Table 3.2 again. The "Class Interval" column depicts age ranges from 1-2 years to 17-18 years.

When asked the width of each of these class intervals, we might at first respond that they had a width of one since 2-1 = 1, 4-3 = 2, and so on up to 18-17 = 1.

However, upon reflection we would probably realize that this couldn't be right since the 1-2 age range contained one and two year olds. The class interval width (or class interval range) would have to be two.

The class interval width is not the difference between the two numbers showing the top and bottom of the range (e.g., 1-2, 3-4, 5-6). Rather, it is the difference between the real upper limit and the real lower limit of the interval.

Table 3.2: Patient Ages

Class
Interval frequency




17-18_____________5
15-16 ____________12
13-14 ____________13
11-12 ____________14
9-10_____________ 15
7-8______________ 18
5-6______________ 21
3-4______________ 19
1-2______________ 23

n = 140

The class intervals are the range of numbers in each category, {1-2, 3-4, 5-6, . . . , 17-18} Each ot these intervals has a width of two. (Actually, the intervals would extend past 2 or 3 to include the decimal numbers in one of those categories too. The real limits take into account the space between the adjacent reported limits. For example, for class intervals 3-4, 5-6, and 7-8, the real limits would be 2.5-4.5, 4.5-6.5, and 6.5-8.5.

Answer 2

Hi,

Look at this example:

Class Interval Width (Interval Range)

Let us look at Table 3.2 again. The "Class Interval" column depicts age ranges from 1-2 years to 17-18 years.

When asked the width of each of these class intervals, we might at first respond that they had a width of one since 2-1 = 1, 4-3 = 2, and so on up to 18-17 = 1.

However, upon reflection we would probably realize that this couldn't be right since the 1-2 age range contained one and two year olds. The class interval width (or class interval range) would have to be two.

The class interval width is not the difference between the two numbers showing the top and bottom of the range (e.g., 1-2, 3-4, 5-6). Rather, it is the difference between the real upper limit and the real lower limit of the interval.

Table 3.2: Patient Ages

Class
Interval frequency




17-18_____________5
15-16 ____________12
13-14 ____________13
11-12 ____________14
9-10_____________ 15
7-8______________ 18
5-6______________ 21
3-4______________ 19
1-2______________ 23

n = 140

The class intervals are the range of numbers in each category, {1-2, 3-4, 5-6, . . . , 17-18} Each ot these intervals has a width of two. (Actually, the intervals would extend past 2 or 3 to include the decimal numbers in one of those categories too. The real limits take into account the space between the adjacent reported limits. For example, for class intervals 3-4, 5-6, and 7-8, the real limits would be 2.5-4.5, 4.5-6.5, and 6.5-8.5.


I hope this helps you.

Answer 3

Hi,

Look at this example:

Class Interval Width (Interval Range)

Let us look at Table 3.2 again. The "Class Interval" column depicts age ranges from 1-2 years to 17-18 years.

When asked the width of each of these class intervals, we might at first respond that they had a width of one since 2-1 = 1, 4-3 = 2, and so on up to 18-17 = 1.

However, upon reflection we would probably realize that this couldn't be right since the 1-2 age range contained one and two year olds. The class interval width (or class interval range) would have to be two.

The class interval width is not the difference between the two numbers showing the top and bottom of the range (e.g., 1-2, 3-4, 5-6). Rather, it is the difference between the real upper limit and the real lower limit of the interval.

Table 3.2: Patient Ages

Class
Interval frequency




17-18_____________5
15-16 ____________12
13-14 ____________13
11-12 ____________14
9-10_____________ 15
7-8______________ 18
5-6______________ 21
3-4______________ 19
1-2______________ 23

n = 140

The class intervals are the range of numbers in each category, {1-2, 3-4, 5-6, . . . , 17-18} Each ot these intervals has a width of two. (Actually, the intervals would extend past 2 or 3 to include the decimal numbers in one of those categories too. The real limits take into account the space between the adjacent reported limits. For example, for class intervals 3-4, 5-6, and 7-8, the real limits would be 2.5-4.5, 4.5-6.5, and 6.5-8.5.


I hope this helps you.

Answer 4

One thing about statistics is that terms are not as universal as in early mathematics. These are not necessarily universal terms and sound like the same thing to me. I would need to see the context to know if there is a difference.

The only distinction I can think of would be if 'class interval' was referring to one particular interval and 'class width' referred to the width of the intervals (which should all be the same).

Sorry I can't be more help than that.

Answer 5

Like pi r squared said (here's a joke: pie are not square, pie are round hahahah anyway) the interval is the actual real number interval (aka "between a and b") while the width is the length of the interval (i.e., b-a)