Using geometric sequence concepts, it is found that:
a) The rule is:  .
.
b) An exponential relationship exists between the two variables.
<h3>What is a geometric sequence?</h3>
A geometric sequence is a sequence in which the result of the division of consecutive terms is always the same, called common ratio q.
The nth term of a geometric sequence is given by:

In which  is the first term.
 is the first term.
A geometric sequence represents an exponential relationship between the variables.
In this problem, considering that the first-place finisher wins half of $1.500.000 in total prize money, and each finisher earns half of the one who finished above, the first term and the common ratio are given by:
 .
.
Hence the nth term of the sequence is given by:

More can be learned about geometric sequence concepts at brainly.com/question/11847927
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