Respuesta :
The minimum score he need to make on his fourth test so that his test average is at least an 80 is 88 .
What is average?
The average is defined as the mean value which is equal to the ratio of the sum of the number of a given set of values to the total number of values present in the set.
Average = [tex]\frac{Sum of total data }{Number of data }[/tex]
According to the question
Dan has grades on his first three algebra tests is 74, 78, 80 .
minimum score does he need to make on his fourth test so that his test average is at least an 80
Now ,
Let fourth test score be x .
and minimum average needed is greater than or equal to 80 .
By applying average formula :
Average = [tex]\frac{Sum of total data }{Number of data }[/tex]
substituting the values
80 ≤ [tex]\frac{74 + 78+80+x}{4}[/tex]
320 ≤ 232 + x
88 ≤ x
i.e
x should be greater than or equal to 88
Therefore ,
fourth test score should be greater than or equal to 88 to get average at least 80.
Hence, the minimum score he need to make on his fourth test so that his test average is at least an 80 is 88 .
To know more about average here:
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