Sharp EL-9900 User Manual
162
Chapter 10: Statistics & Regression Calculations
11 Rg_x
–1
Rg_x
–1
(list name for x, list name for y [, frequency list] [,
equation name to store])
Finds the regression curve using the reciprocal function. (recipro-
cal regression)
Formula: y = a
+
bx
-1
Parameters: a, b, r, r
2
12 Rg_ax
b
Rg_ax
b
(list name for x, list name for y [, frequency list] [,
equation name to store])
Finds the regression curve using the power function. (power
regression)
Formula: y = ax
b
Parameters: a, b, r, r
2
13 Rg_logistic
Rg_logistic
(list name for x, list name for y [, frequency list] [,
equation name to store])
Finds the regression curve using the logistic function. (logistic
regression)
Formula: y = c
÷
(1
+
ae
-bx
)
Parameters: a, b, c
14 Rg_sin
Rg_sin
([iterations,] list name for x, list name for y [, fre-
quency list] [, period] [, equation name to store])
Finds the regression curve using the sine function.
The calculator will fit a sine curve for unequal and equal spacing.
Formula: y = a sin(bx
+
c)
+
d
Parameters: a, b, c, d
Note:
The default iterations value is 3. The user may specify the value
up to 25. To raise the accuracy, set the iterations value to 25 and
enter 2
π/b to the period, where b = result obtained from the
calculation beforehand.