Cell phones and personal communication systems have become increasingly popular with all segments of our society. According to the Strategis Group, the number of cellular and personal communications systems subscribers in the United States has increased dramatically since 1990, as shown in the table at the right. Use the information in the table to write an exponential equation that can be used to model the growth in the number of cell phone and personal communication system subscribers in the United States. (Round numerical values to the nearest tenths place.)
