A random sample of state gasoline taxes (in cents) is shown here for 12 states. Use the data to estimate the true population mean gasoline tax with 90%confidence. Does your interval contain the national average of 44.7 cents?

38.4     40.9     67     32.5     51.5     43.4
38        43.4     50.7  35.4     39.3     41.4

For Exercises assume that all variables are approximately normally distributed.