Amusic producer is making a list of vocalists needed to record an album. for each day of recording, a different number of vocalists are needed. the first day, eight vocalists are needed. each day after that, the number of vocalists needed doubles. the producer must pay by the day for each vocalist. to find the total price, the producer needs to know how many vocalists sang in total at the end of the 10th day. use a series to find the sum after the 10th day.