Respuesta :
Lets say Alexis received 85, 89, 92, and x points in her four tests.
Average of a data set or the mean of a data set, we need to add all the values together and divide by the number of values in the set.
So here 85, 89, 92, and x are the values of the data set and the number of values are 4 (since there are 4 tests).
[tex]Avg=\frac{sum}{n}[/tex]
where 'n' represents the number of values and sum represents the total sum of the values.
Here we need to know how much Alexis need to score in her next test so that she can have an average of 90.
So we know the value of average that is 90.
Now,
[tex]90 = \frac{85+89+92+x}{4}[/tex]
Solving for 'x' we get:
[tex]90=\frac{266+x}{4}[/tex]
[tex]266+x=90 \times 4[/tex]
[tex]266+x=360[/tex]
Therefore,
[tex]x=360-266=94[/tex]
So, Alexis need to score at least 94 on her next test in order to have an average of at least 90.
