Taken together, substance abuse costs the united states over a year. a. half a billion dollars b. a billion dollars c. half a trillion dollars d. a trillion dollars

Which is relatively better: a score of 76 on a psychology test or a score of 22 on an economics test? scores on the psychology test have a mean of 90 and a standard deviation of 13. scores on the economics test have a mean of 52 and a standard deviation of 10.