We can use an exponential model to represent this situation.
The model would be y=a(b^x).
Where a and b are constant values. a would be 450 since it is the value when x=0. To find b we would have to make an exponential regression with the values of the table. Using a calculator for this purpose we find that the value of b is 0.931 rounded to 3 decimal places.
Using the model to predict the value of y at x=23, we have
y=450(0.931)^(23) (Replacing the values)
y=86.91 (Raising 0.931 to the power of 3 and multiplying)
The answer would be 86.9 degrees (Rounding the answer to the nearest tenth).