in jennifers anatomy and physiology class, her grade is determined by dropping the lowest score out of 10 tests and averaging the remaining 9 test scores. jennifer has erned the following scores on the first 9 tests: 85%, 89%,93%, 96%, 90%, 89%, 92%, 91% and 82%. what does jennifer need to earn on her 10th test in order to receive at least an 80% in the class.

Question

whpalmer4 · Answer

The lowest score so far is 82%.  We'll drop that.  The average of 9 scores is going to be the sum of the 9 scores divided by 9.  She wants that to equal 80%, so we add the highest 8 scores + x, divide by 9, and that equals 80%.  

$$\frac{85 + 89 + 93 + 96 + 90 +89 + 92 + 91 + x}{9} = 80$$
Solve for $x$ and you've got the minimum score needed.

You should also do the calculation without dropping any scores, to see if she needs to take the 10th test at all.