Texas Instruments TI Programmable 57 User Manual

As
most
of
us
progress
through
school
or
business,
there
will
be
times
when
we
would
like
to
predict
the
outcome
of
some
future
event
—
based
on
our
knowledge
of
how
similar
things
have
gone
in
the
past.
You
might
want
to
predict
the
effects
of
changes
in
diet
on
animal
growth
in
the
biology
lab.
Or
if
you're
a
businessman,
you
might
want
to
predict
what
effect
an
increase
in
advertising
will
have
on
product
sales.
In
either
case
you
want
to
be
able
to
take
a
known
set
of
data,
and
use
it
to
establish
a
straight
line
graph,
and
then
predict
from
the
line
what
the
outcome
should
be
in the
future.
Dat
Regression
Ae,
point
ortrendline
The
way
you
normally
do
this
is
to
noorig
‘draw’ a linear (straight) line that
best represents the graph of all of
your known data or test points. Then
you can extend the line either way to
predict similar events. Data points
are usually expressed as two
numbers, an x coordinate and a
RAMEE)
=
y
coordinate
for
each
point
you're
1) : plotting.
Determining and drawing the best straight line through a variety of data
points
is
pretty
much
a
hit
or
miss
matter
when
drawing
a
graph.
With
your
calculator,
however,
you
can
take
this
program
and
handle
several
aspects of the problem easily.
Ya
’
First
of
all,
any
straight
line
graph
can
be
expressed
as
the
equation:
y = mx + b. Here mis the slope of the line, and b is called the ‘y intercept"’.
The
slope
(m)
of
the
line,
is
the
ratio
of
its
“rise”
to
its
“run”
and
the
intercept (b) is where the line crosses the y axis. Once you know the slope
and intercept of a line you can easily draw it. Then, with your graph you
can extend the line to use it in making calculations and predictions with
your data — as we'll show.
With your calculator, you can calculate the slope and intercept of a line
through your data points. Finding these values can be rather involved,
however, and this is an area where programmability will bring a real
payoff. The formula for calculating the slope is given by:
n
=. MY
m= os ~ x
—

Texas Instruments TI Programmable 57 Specifications

General

Brand	Texas Instruments
Model	TI Programmable 57
Category	Calculator
Language	English