HP HP-15C - 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.
6.61v
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.