Answer:
![y=128((1)/(2) )^(x-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/2gynwzrp8o1z6mg8vka4z9j0gvoc0ifbnz.png)
Explanation:
This problem models a geomatric sequence, because each new element is half of the last one.
A geometric sequence is defined as
![a_(n)=a_(1)r^(n-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/geo2f4d6xwth35c67s1ejasyqusprr9vrm.png)
Where
is the position of the element,
is the first element and
is the reason that creates the sequence.
In this case, we have
,
![r=(1)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cooxzjpe4di4h0wimc8uucbnebnnaz4b7m.png)
Replacing this values, we have
![a_(n) =128((1)/(2))^(n-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/rlv1bnkbb44hp9zc8gprhn8eux7x9jschr.png)
Where
is the independent variable and
is the dependent variable.
Therefore, the function that relates the number of rounds and the number of players advaincing to the next round is
![y=128((1)/(2) )^(x-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/2gynwzrp8o1z6mg8vka4z9j0gvoc0ifbnz.png)