The Manga Guide to Statistics

40 Chapter 2

The other day, I went

bowling with a the

girls in my homerm

cla.

Did you knock

over any pins?

What?! I' knock you

over, you pinhead!

A the girls

in your

homerm

cla...That

must be a lot.

We, there were

18 of us, so we

formed 3 teams

of 6, and played

1 game.

These are

the score

cards.

2. Mean (Average)

CO

BREAK!

I'm gd at

bowling!

Just

kiing!

Geing the Big Picture: Understanding Numerical Data 41

Oh! This is gd

material for

today's cla.

Is this you? "rui-rui"

is your nickname?

Yes, they ca me

"rui-rui," and I

scored 86.

Roughly speaking,

your score sms

to be around the

average for your

team.

Do you understand

that the average is

the score we can

expect a person

on your team to

receive?

Of course I do.

The average

is the mile

score of a

team.

If I am above

average, you

have to buy

me a piece of

cake.

Why don't we

try calculating

the average.

Results of bowling tournament

Team A

I' have to think

about that.

Team B Team C

SCORE SCORE SCORE

So

what?

Rui-Rui

Jun

Yumi

Shizuka

Touko

Kaede

Kimiko

Megumi

Yoshimi

Mei

Kaori

Yukiko

Shinobu

Yuka

Sakura

Kanako

Kumiko

Hirono

Player Player Player

Since the game was

played betwn

teams, I gue you

compared the sum of

the scores of each

team.

You get the average by

dividing the sum of the

scores by the number of

team members, so...

Thus, your team's

average is 87.

Would you buy me

a piece of cake?

Exactly.

Team c is so

strong.

And rui-rui's

score was

86.

Team A

Team B

Team C

You upset me

WHY?

42 Chapter 2

You have

no right

to ca me

Rui-rui.

Don't be so

angry...

S...

Soy

Oh,

we.

Instead of buying you

cake, I' give you a

sma tip.

What's that?

The average is caed the

mean in statistics. And the mean

we were talking about just

now is something caed the

arithmetic mean, to be precise.

There are other types of mean,

such as geometric mean and

harmonic mean. You do not

have to learn the formulas

now, but I suest you

remember these names.

T bad this

tip is not as

delicious

as cake.

Geometric mean

Harmonic mean

Geing the Big Picture: Understanding Numerical Data 43