3n - 1 = 8 two step equations

Which graph represents the solution of the inequality?

The following graph shows the consumer price index (cpi) for a fictional country from 1970 to 1980? a.) 1976 - 1978b.) 1972 - 1974c.) 1974 - 1976d.) 1978 - 1980

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?