I think its 149/ 490. Not sure, but pretty confident. Hope this helps.
Look at the table for the people that used Lithium.
There are 18 relapses, 6 No relapses with a total of 24 people.
The relative frequency for relapse, would be dividing the number of relapses by the total number of people.
This would be D. 18 / 24 = 75%
Multiply 5% by 229
So, .05 x 229 = 11.45
$11.45 tax