In Tropical Shipping & Constr. Co. v. Askew, 364 So. 2d 433, 436 (Fla. 1978), the Court recognized the balance that must be struck between the obligation to construe tax exemption statutes narrowly and the responsibility to ensure that the construction adheres to constitutional requirements by not "denying businesses engaged in interstate or foreign commerce their right to be free from undue state interference." Id. at 435. Guided by these principles the Court determined: First we note that Florida has the right to tax interstate or foreign commerce to impose "a fair share of the cost of the local government. " Freeman v. Hewit, 329 U.S. 249, 67 S. Ct. 274, 91 L. Ed. 265 (1947). The United States Supreme Court has upheld the usage of a pro-ration formula to fairly apportion the cost of doing business in the state. Braniff Airways v. Nebraska State Board of Equalization and Assessment, 347 U.S. 590, 74 S. Ct. 757, 98 L. Ed. 967 (1954). Thus Florida's pro-ration of its sales and use tax is a valid method for insuring that businesses engaged in interstate and foreign commerce pay their fair share. Id. at 436.