Sandra's minimum average at least score on the fifth test is 56.
What is an average?
The average of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set.
For the given situation,
The scores are 87% , 92% , 76% , and 89%.
The average is 80%
Let the unknown score be 'x'
The formula for average is
[tex]Average = \frac{Sum of all items}{Number of items}[/tex]
On substituting the above values,
⇒ [tex]80=\frac{87+92+76+89+x}{5}[/tex]
⇒ [tex]400=344+x[/tex]
⇒ [tex]x=56[/tex]
Hence we can conclude that Sandra's minimum average at least score on the fifth test is 56.
Learn more about the averages here
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