HP HP-11C - Page 68

66 Section 3: Numeric Functions
T ¢ ?:
2= -
Y| y /
x> [
Keys =
ssTxe
Example. Using the statistics saved from the previous example, if
Voltz wishes to predict coal production (y) for 1977, she keys in an
estimate of electrical production (a “known’ x-value) for 1977 and
presses (f](7.r]. Because the correlation coefficient for Voltz’s data is
automatically included in the calculation, she can view how closely
her data fits a straight line by simply pressing after the y
prediction appears in the display.
Keystrokes Display
7.1417 7.1417 Voltz’s estimate of 1977
electrical output.
2.0046 Predicted coal production
for 1977.
X=y 0.9211 The data closely
approximates a straight
line.