Quadri-, quadru-, quadr-is a Latin prefix related to the verb quadrare âto make squareâ, quadratus âsquareâ etc. Quad is simply an English shortening of quadrangle, quadruplet etc. So quadri-and quad are actually the same word.
The Washington state sales tax rate is 6.5% , and the average WA sales tax after local surtaxes is 8.89% 1  . Groceries and prescription drugs are exempt from the Washington sales tax. 2  Counties and cities can charge an additional local sales tax of up to 3.1%, for a maximum possible combined sales tax of 9.6%.
1 This is comprised of a 5.82 percent federal rate and an average 11.23 percent state-local tax rate. 2  The five states with the highest state-local rates are: Washington State (18.6 percent), Nebraska (18.48 percent), New York (17.74 percent), Florida (16.55 percent), and Illinois (15.81 percent).