if the taxable income is 3,000..what is the federal income tax according to this chart,

if income is over 0
but not over 23,350
the tax is 15percent
of the amount over 0

besides the answer can you show me how you got the answer

The tax is 15% of $3,000 or $450.

The taxable income of $3,000 is between 0 and $23,350. The amount over 0 is $3,000 -- so you figure the 15% tax on $3,000.