Definitions Complement rule: P(A^(C))=P(not A)=1-P(A) Addition rule for disjoint or mutually exclusive events: P(A ∪ B)=P(A or B)=P(A)+P(B) Solution The probability P(0<= z<= 1) is given in the row with z=1.0 and in the column with .00 of the normal probability table in the appendix: P(0<= z<= 1)=0.3413 The standard normal distribution is symmetric about 0: P(-1<= z<= 1)=2P(0<= z<= 1)=2(0.3413)=0.6826