Sharp EL733A EL-733A Operation Manual - Page 78

REYING

IN

DATA

The

two

numbers

in

the

statistical

data

pairs

that

you

use

in

two

-variable

statistics

are

called

fi

e

and

"y."

To

key

in

a

data

pair,

key

in

x,

press

the

((z

key

(which

is

thmerAST

To

AT

n

mode

meaning

of

the

key),

key

in

y,

and

press

i

correct

a

data

entry,

key

in

the

incorrect

x,

press

the

gra))

key,

key

in

the

incorrect

y,

and

press

(

-1

.

As

an

example,

assume

you

invested

in

a

company

in

January

of

1982.

The

value

of

the

stock

has

increased

in

value

steadily

according

to

the

following

table.

January

of:

$

Stock

Value

1982

45'000

1983

46'976

1984

49'254

1985

51770

1986

52'624

1987

54'190

What

has

been

the

average

value

of

your

investment

during

those

years?

And,

a

more

interesting

question

is:

if

the

rate

of

increase

in

the

stock

value

can

be

approximated

by

a

straight

line,

what

will

your

stock

be

worth

in

the

year

2000?

You

have

six

data

pairs

to

key

in

for

this

problem.

They

are

(1982,

45'000),

(1983,

46'976),

(1984,

49'254),

(1985,

51'770),

(1986,

52'624),

(1987,

54'190).

The

keystrokes

used

to

key

in

this

data

are

as

follows:

(Mode:

STAT)

1982

Icr,AI

45'000

1983

AA

46'976

[DATA)

[DATA)

152

1984

gra))

49'254

[DATA)

1985

Kra))

51'770

I

DATA)

1986

Kral

52'624

(DATA)

1987

(Cr,Y)1

54'190

(DATA)

Remember

that

((ra))

is

the

STAT

mode

meaning

of

the

ISM)

key.

FlY

is

not

the

second

function

of

the

(OM)

key,

so

you

do

not

have

to

press

2ciFI

fi

rst

(you

can

if

you

wish

though).

As

you

key

in

the

above

six

data

pairs,

you

will

notice

that

the

calculator

keeps

track

of

the

pair

that

you

are

on

by

counting

them

in

the

display.

This

number

that

it

shows

in

the

display

is

called

"n."

At

any

time,

you

can

see

how

many

data

pairs

have

been

keyed

in

by

pressing

[2nd

Ej

.

At

the

end

of

keying

in

the

data,

n

is

equal

to

6.00,

and

6.00

is

what

should

be

showing

in

the

display.

Once

you

have

the

data

keyed

in,

you

are

fi

rst

after

the

answer

to

the

question:

what

is

the

average

value

of

your

stock

over

the

years?

To

see

this

answer

press:

(2ndn

M

Result:

49'969.00

The

M

key

returns

the

mean

of

the

y

values.

In

this

case,

you

entered

the

stock

value

as

the

y

component

of

each

data

pair,

so

El

returns

the

average

stock

value

over

the

years.

The

next

question

you

want

to

answer

is:

if

the

increase

in

value

can

be

approximated

by

a

straight

line

(in

other

words,

if

the

trend

of

the

last

fi

ve

years

stays

constant)

what

will

the

stock

value

be

in

January

of

the

year

2000?

To

answer

this

question,

simply

use

the

keystrokes:

2000

FP)

[j

Result:

78'936.29

153

Sharp EL733A EL-733A Operation Manual - Page 78

Sharp EL733A Manual

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