The Manga Guide to Statistics

Relative

frequency?

What's that?

The number of values included in a cla

The total number of values

Something similar to

percentage. Percentage

is familiar to you, isn't it?

It's the ratio against

the total when the

total is considered 1.

This is the

formula.

There are 18 shops on

the third flr, and

there are 50 shops in

this ma...So...

Very gd! The relative frequency

of ramen shops in cla 700–800

yen—in other words, shops with cla

midpoint 750 yen—is 0.36. You get the

percentage by multiplying by 100, so

this is equal to 36%.

Oh, no! This

is geing

mathematical...

Relative

frequency

=

= 0.36!

18

—

50

36

—

100

=

Geing the Big Picture: Understanding Numerical Data 37

Are you

foowing

me?

50 Best Ramen Shops Frequency Table

cla (equal

or greater/

le than)

cla

midpoint

fre-

quency

relative

frequency

Sum

Sigh...This

is a math

after a.

To suarize

what I have

explained up

to this point,

lk at this

table.

We, it is.

Maybe this sms

diicult because

there are t many

numbers. It may

become easier if

we use a graph.

If we describe a

this using...

a bar chart caed a

histogram...

38 Chapter 2

500–600

600–700

700–800

800–900

900–1000

550

650

750

850

950

4

13

18

12

3

0.08

0.26

0.36

0.24

0.06

50 1.00

Our horizontal

axis shows

the variables—

in this case, the

price of ramen.

The width of

each bar is the

range of the

cla.

The center

of each bar

is the cla

midpoint.

The

vertical

axis

Is this

easier to

understand?

WE...

I fl

like I am

sort of

begiing

to...

Grasp the

overa

image of

ramen

prices.

To "fl like"

grasping is

important. The

frequency table

and histogram

exist to give you

a beer sense

of a the data.

Is that so?

Histograms Based on

50 Best Ramen Shops Frequency Table

Histogram (vertical axis is frequency)

Histogram

(Vertical axis is relative frequency)

shows the

frequency

in the first

histogram

and the relative

frequency in

the second

histogram.