Answer
0.1839
Work Step by Step
We calculate the z-scores:
$z_1=\frac{x-\mu}{\sigma}=\frac{56-50}{7}=0.86$
$z_2=\frac{x-\mu}{\sigma}=\frac{66-50}{7}=2.29$
We look up $z_1$ in Table V and get the area to the left of 0.8051.
We look up $z_2$ in Table V and get the area to the left of 0.9890.
We subtract the two areas to get the area in between:
0.9890-0.8051=0.1839