Answer:
9
Step-by-step explanation:
5,7,8,10,12,12
5+7+8+10+12+12=54
54/(how many numbers there are, which is 6)=9.
Your mean value is 9.
If you would like to solve 9 5/9 - 6 5/6, you can calculate this using the following steps:
9 5/9 - 6 5/6 = 86/9 - 41/6 = 516/54 - 369/54 = (516 - 369) / 54 = 147/54 = 49/18 = 2 13/18
The correct result would be 2 13/18.
It will be 10 feet in 14 second