Mean=0, sd=1, if P(-b<z<b)=0.8566.find b?

Answer 1

b= 1.463

use z tables or z calculator

z=.8566

Pr(-1.463<x<1.463)

mean=0

sd= 1

the empirical rule 68-95-99.7

shows 1<b<2

1<1.463<2

68<85.66<95