(a) Whenever the State Board of Education finds that racial imbalance exists in a public school, it shall notify in writing the board of education having jurisdiction over said school that such finding has been made.

      (b) As used in sections 10-226a to 10-226e, inclusive, “racial imbalance” means a condition wherein the proportion of pupils of racial minorities in all of the grades of a public school of the secondary level or below taken together substantially exceeds or falls substantially short of the proportion of such public school pupils in all of the same grades of the school district in which said school is situated taken together.