What characteristic is true for all relations that are functions? The graph of the relation passes the vertical line test.
O Every x-value in the relation has at least one y-value.
O Every y-value in the relatior has exactly one x-value
O The graph of the relation passes the horizontal line test

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