HP NW280-200X User Manual page 209

Predict values
Statistics 2Var app
(m) of the regression line is 425.875 and the y-
intercept (b) is 376.25.
Let's now predict the sales figure if advertising were to go
up to 6 minutes.
14. Return to the Plot
view:
P
The trace option is
active by default.
This option will move
the cursor from data
point to data point as you press
move from data point to data point, the
corresponding x- and y-values appear at the bottom
of the screen. In this example, the x-axis represents
minutes of advertising and the y-axis represents sales.
However, there is no data point for 6 minutes. Thus
we cannot move the cursor to x = 6. Instead, we need
to predict what y will be when x = 6, based on the
data we do have. To do that, we need to trace the
regression curve, not the data points we have.
15. Press \ or =
the cursor to trace
the regression line
rather than the data
points.
The cursor jumps
from whatever data
point it was on to the
regression curve.
16. Repeatedly press
If the x-value is not shown at the bottom left of the
screen, tap
When you reach x = 6, you will see that the
value (also displayed at the bottom of the screen)
>
to set
> until x = 6.
.
or < . As you
PREDY
203