There is exempted from the computation of the amount of the sales tax the gross receipts from sales of tangible personal property to a common carrier, shipped by the seller via the purchasing carrier under a bill of lading whether the freight is paid in advance, or the shipment is made freight charges collect, to a point outside of this state and the property is actually transported to the out-of-state destination for use by the carrier in the conduct of its business as a common carrier.