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
$10.50 an hour. all you need to do is take 36.75 divided by 3.5
Answer:
Assuming the repetitive part is 152, i.e. the original repeating decimal is
A=3.152152152....
then
1000A=3152.152152152152....
subtract A
1000A-A=3152.152152....-3.152152152....
999A=3149
A=3149/999=3+152/999=3 152/999
Therefore
3.152152152.... = 3149/999 or 3 152/999
Advice : use cy math.com on your computer
or photo math on your phone
I believe that it deals with standard deviations you need to look at a graph of the standard deviation.