I'm trying to get a degree, so if the gas price is going up 18%, do I add them all together or multiply them?

(a) Relative frequency distribution Response Frequency Relative frequency New tolls 412 0.41 increase gas tax 181 0.18 no new roads 412 0.41 Note : Total frequency = 412+1818+412=1005 relative frequency for New tolls = 412/1005 = 0.41 etc b) 18% respondents indicated they would like an increase in gas tax c) Frequency bar is given below