So, the first thing you need to do is find the appropriate criteria on the chart. We're looking for the number of patients who are male and have type-b blood. The number in this case is 99.
Now, we look for the total number of patients. This is 714.
In order to find percentage you can use this "formula" to help you
Part/Total = % (Percent)/ 100.
Fill in what you know, we know the part is equal to 99 and the total is equal to 714. So,
99/714 = x/100
Cross multiply.
9900 = 714x
Solve accordingly; divide both sides of the equation by 714 to isolate the variable.
x = 7.21212121....
We round this down to 7.2%! I hope this helped! :)
