pls help

The table below shows the function C(t). This function gives the concentration of carbon dioxide (CO2) in the atmosphere, measured in parts per million (pipm), t years after 1800. C(t) 160 316.91 165 320.04 170 325.68 175 331.09 338.7 345.86 190 354.17 195 360.63 200 369.41 What is the concentration of CO2 in the atmosphere in the year 1960? In what year does the concentration of CO2 equal 338.7 ppm