For each function, state weather it’s linear

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

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

Is experimental probibilty the same as the observed frequency in math? i need the answer asap!