Step-by-step explanation:
step 1. A geometric sequence is found by multiplying subsequent term by a number r.
step 2. 106.8/178 = 0.6. 64.08/106.8 = 0.6. a = 0.6. note that a geometric series must have the same number when dividing successive terms.
step 3. an = ar^(n - 1) = a(0.6)^(n - 1)
step 4. given a1 = 178. an = 178(0.6)^(n - 1)
step 5. therefore a11 is the 11th term!
step 6. a11 = 178(0.6)^10 = 1.0763 = 1.08.
