Answer
$0.6826$
Work Step by Step
$\text{z-score}=\frac{\text{data item-mean}}{\text{standard deviation}}$
Hence here the z-score is: $\frac{67-72}{5}=-1,\frac{77-72}{5}=1$
Then, using the table: $P(67\leq x\leq 77)=P(x\leq 77)-P(x\leq67)\approx P(z\leq1)-P(z\leq-1)=0.8413-0.1587=0.6826$
