Latisha is determined to do well in school this year. Her goal is to maintain at least an $85\%$ average in all of her courses.  

1. Latisha started with two scores on tests, $72\%$ and $89\%$. Confirm that the average of these two scores is $80.5\%$. Show your work.

   Hint (a):

   To find an average, add the scores Latisha received together and divide by the number of scores she had.

   Answer (a):

   $\frac{(72+89)}{2}=80.5$

2. Latisha’s third score was $90\%$. Use her scores from part (a) to figure out her average now. Be sure to show your work.

   Hint (b):

   Remember you now need to add $90\%$ to the scores and divide by the number of scores you have now.

   Answer (b):

   $83.67\%$