In Prince Edward Island, Canada, our sales tax is calculated as follows:
10% of cost of article or service, then 7% on top of that! The 10% is the provincial sales tax, the 7% is federal - in some Canadian provinces, these taxes are combined and total only 15%. (Only?)
In response to "which" tax is dedicated to our national insurance program, I am assuming you are referring to Medicare. To the best of my knowledge, most Canadian taxes are not "dedicated" to one program or the other; however, the income taxes we pay to the federal government form the large part of any national program. We pay income taxes, both provincial (read state) and federal, in varying amounts, depending on the provinces in which we live - but for a middle income earner, in this province we pay about 30 to 35% of our total income in these combined taxes.
Lower income earners pay little or no taxes (they may receive rebates on amounts deducted from their pay cheques, if they have dependent children, etc.). Higher income people pay proportionately higher amounts to income taxes.
And we also pay property taxes - in this province, if you live in an unincorporated area, you pay provincial property taxes only; if you live in an incorporated municipality, you pay municipal and provincial taxes.
Nevertheless, I am a proud Canadian, and I enjoy living my tiny Island province!! (On the other hand, if I paid less taxes, maybe I could visit WDW more often!)