Answer:
9.8
Step-by-step explanation:
a geometric sequence means we multiply the previous element by a certain factor to get the next element.
so, all we need to do is determine the factor used to go from one element in the list to the next.
a1 = 9
a2 = 88.2
a3 = 864.36
a4 = 8470.728
the simplest case is usually the case from a1 to a2.
a2 = a1×f
88.2 = 9×f
f = 88.2/9 = 9.8
we are finished here.
but we can control our result and verify with the other given elements.
88.2 × 9.8 = 864.36
and that is a3. fits.
864.36 × 9.8 = 8470.728
and that is a4.
so, all fits, we are correct.
