Explanation:
To find d(1), you need to substitute n with 1 in the formula:
d(1) = 40(0.5)^1 d(1) = 40(0.5) d(1) = 20
To find d(4), you need to substitute n with 4 in the formula:
d(4) = 40(0.5)^4 d(4) = 40(0.0625) d(4) = 2.5
So, d(1) is 20 and d(4) is 2.5.