Instead of doing your problem, I will do one EXACTLY in every detail like
your problem. Then you can use it as a model to do yours by:
I will do this one:
Find a possible formula for a power function with the properties that
g(3)=4/3 and g(4)=4/9.
I start by assuming the general power formula for g(x)


I substitute x=3 and set that equal to 4/3:




Then I substitute x=4 and set that equal to 4/9:




Then I divide equals by equals dividing g(4) by g(3)








I substitute that in 





I multiply both sides by 27 to clear of fractions:




Therefore my power function 

becomes
Answer: 

Now do your problem exactly the same way I did mine.
Edwin