Answer:
There were written records by studying aircrafts before historians know about the past.
Step-by-step explanation:
Answer:
20.8 12
Step-by-step explanation:
Answer:
2.4
Step-by-step explanation:
To find the mean absolute deviation, find how much each value is away from the mean, and divide it by the number of numbers you have. In this case, the mean is 5, and the deviation of each number is 4, 2, 0, 2, and 4. Add these up and you get 12. Divide 12 by the number of numbers which you have, which is 5, to get 2.4.