I'm not sure what the options are as this appears to be a multiple choice question, but this probability is as follows:
22-21.9 = 0.1
You round it off adding a zero .
The answer is 1.0
You multiply by 100
You get 100
x = 8
Since x = 8, you can plug in/substitute 8 for "x" in the equation:



2.82842
2.83 You answer is the 4th option
x = 9
Plug in 9 for "x" in the equation



4 Your answer is the 1st option