In order to find the total amount of the shirt including tax, first convert the tax into a decimal:
4.1/100 = 0.041 %
Next multiply the cost of the shirt before tax by the tax in decimal form:
25 * 0.041 = 1.025
After that you will add the tax cost and the shirt cost:
25 + 1.025 = 26.025
Finally round to the nearest cent:
26.03
Hope this helps and let me know if you have more questions!