Answer:
She needs 89 on her last test so that her mean is 73.
Step-by-step explanation:
The mean is the sum of all test scores divided by the number of tests. So
[tex]M = \frac{S}{T}[/tex]
In which M is the mean, S is the sum of the scores and T is the number of tests.
In this problem, we have that:
There are going to be 6 tests, the five previous and the last one. So [tex]T = 6[/tex]
We want an average of 73 for Chang. So [tex]M = 73[/tex]
Her scores are: 73, 79, 72, 59, 66 and x, in which x is her score on the next text. So [tex]S = 73 + 79 + 72 + 59 + 66 + x = 349 + x[/tex]
So
[tex]M = \frac{S}{T}[/tex]
[tex]73 = \frac{349 + x}{6}[/tex]
[tex]349 + x = 73*6[/tex]
[tex]x = 89[/tex]
She needs 89 on her last test so that her mean is 73.
