Agroup of 15 students play different instruments, 6 play piano, 4 play violin and 5 play guitar. a student is chosen at random. what is the probability that the student chosen plays violin or piano?

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