HP 15c Collector's Edition - Page 63

Section 4: Statistics Functions 51
X
NITROGEN APPLIED
(kg per hectare
*
), x
0.00 20.00 40.00 60.00 80.00
Y
GRAIN YIELD
(metric tons per
hectare), y
4.63 4.78 6.61 7.21 7.78
*
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
6.61
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.