Final answer:
The statement is false because growth in preschool children actually slows down, with children typically growing about 5.1 to 7.6 cm (2 to 3 inches) per year.
Step-by-step explanation:
The statement that growth speeds up in the preschool years with the average yearly height increase being 2½ to 3 inches is false. During the preschool years, specifically between the ages of 4 and 6, growth actually slows down. Preschool children typically grow about 5.1 to 7.6 cm (2 to 3 inches) per year in height, which is consistent with the slowed growth rate mentioned.