– E-28 –
Statistical Calculation Formulas
In the statistical calculation formulas, an error will occur when:
Type Regression formula
Linear y = a + bx
Quadratic y = a + bx + cx
2
Exponential y = a • e
bx
Logarithmic y = a + b • ln x
Power y = a • x
b
Inverse y = a + b —
1
x
• The absolute value of the intermediate result or calculation
result is equal to or greater than 1 × 10
100
.
• The denominator is zero.
•
An attempt is made to take the square root of a negative number.
• No solution exists in the quadratic regression calculation.
Normal Probability Calculations
•P(t), Q(t), and R(t) will always take positive values, even
when t<0, because these functions follow the same principle
used when solving for an area.
Values for P(t), Q(t), and R(t) are given to six decimal places.
Σx = x
1
+ x
2
+ ··· + x
n
Σx
2
= x
1
2
+ x
2
2
+ ··· + x
n
2
x =
Σx
n
Σxy = x
1
y
1
+ x
2
y
2
+ ··· + x
n
y
n
Σy = y
1
+ y
2
+ ··· + y
n
Σy
2
= y
1
2
+ y
2
2
+ ··· + y
n
2
y =
Σy
n
σy =
Σy
2
– ny
2
n
sy =
Σy
2
– ny
2
n – 1
sx =
Σx
2
– nx
2
n – 1
σx =
Σx
2
– nx
2
n
t
σx
=
x – x
Standardization conversion formula
EL5060E_En0616.pm65 06/16/2004, 13:1028