Exp/Log Functions 9 Lesson 4.2 - Change in Geometric Sequences QuickNotes Check Your Understanding 1. Write a formula for the sequence given by 2, 10, 50, 250... . com an = 2. 5n - 1 2 . rutic 2 . 5 - 2 2. 5 2.5 3 2. If an is a geometric sequence with a4 = 48 and a7 = 384, find the common ratio, r, and a1. 1=8 12 an = a , . 2 3/8 = 2 ... possible common ratio 48 = a, . 8 For a given sequence, a1 = 22 and a2 = 33. a. Find a3 if the sequence is arithmetic. 21 =6 b. Find a3 if the sequence is geometric. 4. The first week of July was the opening week of the Deluxe Hotel. It had 200 guests that week. In the weeks immediately following this, the bookings decreased by 5% each week. a. How many guests did the hotel have in the 3d week? In the 11th week? b. Write a rule that gives the number of bookings in the nth week. J CALC MEDIC