Question

PLEASE HELP!! Show simple working out

Answer 1

In order to estimate the mean, you need to choose a value to represent the number in each category of accidents. It is often convenient to use the middle value of the range.
.. (4*6 +10*10 +15*6 +20*9)/(6 +10 +6 +9) = 394/31 ≈ 12.7