On four exams, wallace’s grades were 79,93,91, and 68. what grade must he obtain on his fifth exam to have an 80 average?

(79 + 93 + 91 + 68 + x) / 5 = 80

Simplify

(331 + x)/5 = 80

Multiply 5 to both sides to isolate the x.

331 + x = 400

Isolate the x. Subtract 331 from both sides

x + 331 (-331) = 400 (-331)

x = 69

69 is your answer

hope this helps

answer: 1 + 1 = 11

step-by-step explanation:

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.