Chapter 6 - The Normal Distribution - 6-2 Applications of the Normal Distribution - Exercises 6-2 - Page 339: 18

$722.5$ and $861.5$

We have $\mu=792,\sigma=103$, the middle 50% corresponds a lower end and a higher end, lower end probability= $0.5-0.5/2=0.25, z1=-0.675$ (use Table E) higher end probability= $0.5+0.5/2=0.75, z2=0.675$ $\frac{X1-792}{103}=-0.675, X1=722.5$ $\frac{X2-792}{103}=0.675, X2=861.5$ The limits are $722.5$ and $861.5$