9. Unlike the Portuguese, who had rounded Africa and were sailing east toward Asia, Christopher Columbus decided to sail ____________________blank His decision was based on his estimates of the ____________________blank circumference and the sizes of ____________________blank and ____________________blank Unfortunately, Columbus ____________________blank the former and ____________________blank the latter. Although this resulted in a much longer voyage than he anticipated, his estimates probably helped convince ____________________blank and ____________________blank, the two Spanish monarchs who sponsored his voyage.