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127

& LD 10

PROBIT (p) - = 1.76963 + 0.22027(co nc.)
. 1 - 28155 = -1.76963 + 0.22027(co nc.)

0.1 1.76963 - 1.28155
conc. =
0.22027
conc. = . 2 2158 ppm

Z = -1.28155
Prob = 0.1

& LD 90

PROBIT (p) - = 1.76963 + 0.22027(co nc.)

0.9
. 1 28155 = -1.76963 + 0.22027(co nc.)
1.76963 + 1.28155
conc. =
0.22027
conc. = . 13 852 ppm

Z = 1.28155
Prob = 0.9

/
6 & . ! " (rage) % & %6/ 95% & 8 /"' /'1 "5( +/ & 8 /"*
") lower upper

7
V& ! . L, & ! Q DDVP
#& Probit Z-
score +/

!
x & Z-score = 0 6 ' /& Probit (p) = 0.5
*
*0( ( "
x
Y* 5( & & ! Q ''1 5( 50% 5( %
/