To find an average you take the numbers to be averaged and add them together then You take the number and divide it by the number of numbers, in this case 4, and that gives you the average.
on this problem you want to do the opposite. you know the average she wants, an 87, so you multiply it by 4. 87*4=348. then you add the three numbers you have (88,81 and 87) and you get 256.
then you subtract 256 from 348 and you get 92. 92 is your answer to check just add 87+81+88+92=348
348/4=87
87 was the average she wanted.
Hope this helped! good luck :)
Answer: 6 x 10^12
Step-by-step explanation:
Move the decimal to the left so there is one non-zero digit number left of the decimal point. This will be the exponent placed on 10
C
The numbers on the left represent 10 times that number
The numbers on the right are added to the end of the number on the left so
3I1=31 and 4I8=48 and 3I 1 1 2= 31 31 32
