Answer
0.2368
Work Step by Step
We calculate the z-score:
$z_1=\frac{x-\mu}{\sigma}=\frac{55-50}{7}=0.71$
$z_2=\frac{x-\mu}{\sigma}=\frac{70-50}{7}=2.86$
We look up $z_1$ in Table V and get the area to the left of 0.7611.
We look up $z_2$ in Table V and get the area to the left of 0.9979.
We subtract the two areas to get the area in between:
0.9979-0.7611=0.2368