[tex]y=4(0.25)^{x}[/tex]
1) To determine which is the function from the table we need to attentively look for a constant factor in the y-column.
2) As we can see from this table, the factor we can tell that goes from 64 to 16 and then 4 is 1/4. Or in decimal form 0.25. So, we can tell the factor "b" is going to be 1/4 considering this model:
[tex]\begin{gathered} y=a(b)^x \\ y=a(0.25)^x \end{gathered}[/tex]
3) Let's pick one point (0,4) and plug it to find the other elements:
[tex]\begin{gathered} y=a(\frac{1}{4})^x,(0,4) \\ 4=a(\frac{1}{4})^0 \\ a=4 \end{gathered}[/tex]
And finally, we can tell the function is:
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