Kara has 5 exams scores 58,73,85,83, and 79 in her biology class. What score does she need on the final exam to have a mean grade of 70

Her final exam will be her 6th exam. To determine the her final exam  score we can use this equation:

Mean = All scores/6

70 = (58 + 73 + 85 + 83 + 79 + x )/6  ⇒ x stands for the final exam mark

70 = 378 + x /6   ⇒ Multiple both sides by 6 to cancel it out

420 = 378 + x   ⇒ Subtract 378 from both sides to isolate x

420 - 378 = x

42 = x

Therefore, she must get at least 42% on her final to maintain a 70% average.