What score does she need on the next test in order to have an average of 90 on her math tests?

Sally receives the following scores on her math tests: 78, 92, 83, 99. What score does she need on the next test in order to have an average of 90 on her math tests?
More examples:
1. • Civil Service Exam: AV...
2. • AVERAGE | Find the num...
3. • Civil Service Exam Q5:...
4. • Q7&8: Civil Service Ex...
5. • Civil Service Exam: AV...
Basic Math na mahalaga sa Civil Service Exam
Part1: • How to find GCF Greate...
Part2: • Complete: Addition Sub...
Part3: • Decimal Numbers | Addi...
Part4: • Decimal Fraction Perce...
Part5: • Basic Math Word Proble...
Part6: • Ratio and Proportion B...
Part7: • Perform the Indicated ...
Part8: • Find the Value of X | ...
Part9: • What is the number? Wo...
Part10: • What score does she ne...
#CSE
#Math
#CivilServiceExam

[@kristelrodillassalazar1754]

After 6 mathematics tests. Gabriel has a mean score of 78. What score does Gabriel need on the next test to raise his average (mean) to 80? paano po pag- ganito?