Answer
$227085$, and $265515$.
Work Step by Step
We have $\mu=246300, \sigma=15000$,
to satisfy the middle 80% of the market, we need 10% at the lower end and 10% higher,
which means the probability would be 0.1 for the lower and $1-0.1=0.9$ for the higher.
Use Table E, $P(z1)=0.1, z1=-1.281$ for the lower, and $P(z2)=0.9, z2=1.281$ for the higher.
$z1=\frac{X1-246300}{15000}=-1.281, X1=227085$,
$z2=\frac{X2-246300}{15000}=1.281, X2=265515$
The minimum and maximum prices of the houses are $227085$, and $265515$.
