Frusterated by formulas

I have to make a data table for school using excel 2013. I have most of it done, however I am stuck on figuring out the formulas for 2 columns.



Lab 3-2 Into the Woods Weekly Payroll Report Complete.xlsx

I have to figure out the answers to column J & K. The answers are right now manually entered but are suppose to be entered using a formula. Here are the questions my books is asking me to get those formulas.
To get the state tax: State tax is calculated as a percentage of federal tax. Use the tax rate in the Tax Rate table to calculate state tax in column J.
To get Net Pay: Calculate Net Pay in column K, as Gross Pay-Soc Sec.. Medicare, Federal Tax, and State Tax.

Can anyone help me figure out what formulas to use?