Marcie ran the 400-meter race 3 times. her fastest time was 51.3 seconds. her slowest time was 56.4 seconds. if marcie's average time was 53.4 seconds, what was her time for the third race?

52.5 Seconds

Step-by-step explanation:

Let's call, her time for the third race, x.

To find the average (53.4), we add up all the values and then divide this total by the number of values.

So, we will set up our equation.

      56.4 + 51.3 + x

>     = 53.4

                3

To get rid of 3, we will multiply both sides by 3.

>   56.4 + 51.3 + x = 160.2

>   107.7 + x = 160.2

We will subtract 107.7 from both sides to isolate x.

the answer is 5/3x+7/5y+7

answer: 94

step-by-step explanation: 79+91+92+94+94 = 450 divided by 5 (since there are 5 number that are being added) = 90