A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 260.4-cm and a standard deviation of 1-cm. For shipment, 27 steel rods are bundled together.

Find the probability that the average length of the rods in a randomly selected bundle is between 260.6-cm and 261-cm.
P(260.6-cm < $\displaystyle \overline{{X}}$ < 261-cm) = Round to 4 decimal places.

Answers obtained using exact z-scores or z-scores rounded to 2 decimal places are accepted.