What is the value of the fourth term in a geometric sequence for which a1 = 30 and r = 1/2? .

For a Geometric sequence:
a n = a ( n-1 ) * r
In this case: a 1 = 30
a 2 = 30 * 1/2 = 15
a 3 = 15 * 1/2 = 7.5
a 4 = 7.5 * 1/2 = 3.75 = 3 3/4
The value of the fourth term is 3.75 or 3 3/4.

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