Could use some help with this quiz

The customer price index(cpi), which measures the cost of a typical package of customer goods,was 208.8 in 2011 and 244.1 in 2016.let x=11 corresponding to the year 2011 an estimate to cpi into 2013 and 2014. assume that the data can be modeled by a straight line and the trend to continue idenfinitely.use data points to find such a line and then estimate the requested quantities

Grace paid $1.70 for 5 ounces of candy. how much did she pay for 24 ounces?

Can you explain how a table can be used to find a rate of change?