While travelling, john left destination a at 9 am. driving until 7 pm, he travelled a total of 500 miles. the next day, john left at 9 am and drove until 5 pm, covering 270 miles. what was the average speed for both days, while driving?

Weighted Mean Formula;

To use the formula:

1) Multiply the numbers in your data set by the weights;

2) Add the numbers in Step 1 up. Set this number aside for a moment;

3) Add up all of the weights. Divide the numbers you found in Step 2 by the number you found in Step 3;

4) Divide the numbers you found in Step 2 by the number you found in Step 3;

So,

1) 10 x 500 = 5000; 8 x 270 = 2160;

2) 5000 + 2160 = 7160;

3) 500 + 270 = 770;

4) 7160 / 770 = 9.3 was the average speed for both days;