Answer
The average yearly temperature is $72.8^{\circ}F$
Work Step by Step
The average yearly temperature should be approximately equal to the average of the twelve average monthly temperatures during the year.
We can find the sum of the twelve average monthly temperatures:
$S = 54+58+63+70+79+89+93+91+86+75+62+54$
$S = 874$
We can find the average yearly temperature:
$\frac{874}{12} = 72.8$
The average yearly temperature is $72.8^{\circ}F$