HP 15c - Manual (Page 51)

Section 4: Statistics Functions 51
X
NITROGEN APPLIED
0.00 20.00 40.00 60.00 80.00
(kg per hectare *), x
Y
GRAIN YIELD
4.63 4.78 6.61 7.21 7.78 (metric tons per
hectare), y
*A hectare equals 2.47 acres.
Keystrokes Display
´ CLEAR ∑ 0.0000 Clears statistical storage
registers (R
2
through R
7
and
the stack).
´ • 2 0.00 Limits display to two decimal
places, like the data.
4.63
v 4.63
0
z 1.00 First data point.
4.78
v 4.78
20
z 2.00 Second data point.
6.61
v 6.16
40
z 3.00 Third data point.
7.21
v 7.21
60
z
4.00 Fourth data point.
7.78
v
7.78
80
z 5.00
Fifth data point.
l 3 200.00 Sum of x-values, Σx (kg of
nitrogen).
l 4
12.000.00 Sum of squares of x-values,
Σx 2
.
l 5 31.01 Sum of y-values, Σy (grain
yield).
l 6 200.49 Sum of squares of y-values,
Σy 2
.
l 7
1,415.00 Sum of products of x- and
y-values, Σxy.