Answer
6.7 and 4.04
Work Step by Step
We have $\mu=4.8,\sigma^2=2.1, P(z1)=1-0.1=0.9, P(z2)=0.3$
Use Table E $z1=1.281, z2=-0.524$
$z1=\frac{X1-4.8}{\sqrt {2.1}}=1.281, X1=6.66$
$z2=\frac{X2-4.8}{\sqrt {2.1}}=-0.524, X2=4.04$
Conclusion: 10% of hospital stays are longer than 6.7 days,
and thirty percent of stays are less than 4.04 days.
