Question

kelly is playing a computer game to help her learn about science. her scores for the first six games were 10, 12, 10, 8, 14, and 15. how many points does she need to earn on the next game so that her average score for all games is 12 points?
o 3
o 15
o 11.5
o 64

Explanation:

Step1: Calculate sum of first six scores

$10 + 12+10 + 8+14 + 15=69$

Step2: Let the score of the seventh - game be $x$. Set up the average formula

The average of seven scores is $\frac{69 + x}{7}$, and we want this average to be 12. So we have the equation $\frac{69 + x}{7}=12$.

Step3: Solve the equation for $x$

Multiply both sides of the equation by 7: $69 + x=12\times7=84$. Then subtract 69 from both sides: $x=84 - 69 = 15$.

Answer:

B. 15