The width of the actual pool is 156 meters.
Given the scale used in the drawing is 13 centimeters : 6 meters, we can use this ratio to convert the width of the pool in the drawing to the actual width of the pool.
width (actual) = (width (drawing) / 13 cm) * 6 meters
width (actual) = (26 cm / 13 cm) * 6 meters = 2 * 6 meters = 12 meters
So the actual width of the pool is 156 meters