Brianna needs to earn a C in her Geology class. Her current test scores are 65, 67 67, and 93. Her final exam is worth 6 test scores. In order to earn a C Brianna's average must lie between 70 and 79 inclusive. What range of scores can Brianna receive on the final exam to earn a C in the course?

Question

Brianna needs to earn a C in her Geology class. Her current test scores are 65, 67 67, and 93. Her final exam is worth 6 test scores. In order to earn a C Brianna's average must lie between 70 and 79 inclusive. What range of scores can Brianna receive on the final exam to earn a C in the​ course?

PsyDAG · Answer

(65+67+67+93+6x)/10 = 70 (65+67+67+93+6x)/10 = 79 Solve for x in each case.