Question

Going into the final​ exam, which will count as two​ tests, Amelia has test scores of 79 comma 80 comma 70 comma 65 comma and 92. What score does Amelia need on the final in order to have an average score of​ 80?

Answer 1

Answer:

Amelia needs to make 87 on the final.

Explanation:

Let final test grade is x

$Average =\frac{sum\ of\ all\ test\ grades}{number\ of\ tests}$

amelia has taken total number of  5 tests before and the  final exam is equivalent to 2 test therefore total test is 7 in number  

Using the  above formula:

$80 = \frac{79 + 80 + 70 + 65 + 92 + x + x}{7}$

$80 =\frac{386 + 2x}{7}$

$7*80 = 386 + 2x$

 560 = 386 + 2x

174 = 2x

87 = x

Amelia needs to make 87 on the final.