David’s scores on the first three of four 100-point math tests were 86, 92, and 89. What score does he need on his fourth math test to ensure an average score of at least 90?
A.
2003-06-03-00-00_files/i0250000.jpg
B.
2003-06-03-00-00_files/i0250001.jpg
C.
2003-06-03-00-00_files/i0250002.jpg
D.
2003-06-03-00-00_files/i0250003.jpg

Question

David’s scores on the first three of four 100-point math tests were 86, 92, and 89. What score does he need on his fourth math test to ensure an average score of at least 90?
A.
2003-06-03-00-00_files/i0250000.jpg
B.
2003-06-03-00-00_files/i0250001.jpg
C.
2003-06-03-00-00_files/i0250002.jpg
D.
2003-06-03-00-00_files/i0250003.jpg

anonymous · Answer

$$\large \sf \frac{86+92+89+x}{4} \geq 90$$