## Algebra 2 (1st Edition)

$0.937$
Using the table and part a): $P(19.4\lt x\leq 20.4)=P(x\leq 20.4)-P(x\leq19.4)\approx P(z\leq1.6)-P(z\leq-2.4)=0.9452-0.0082=0.937$