The average length of a flight by regional airlines in the united states has been reported as 464 miles. if a simple random sample of 30 flights by regional airlines were to have a mean of 476.9 miles and a standard deviation of 42.8 miles, what would be the test statistics (t-value) if we are to test whether this tend to cast doubt on the reported average of 464 miles or not? use a two-tail test and the 0.05 level of significance in arriving at your answer. (specify your answer to the 3rd decimal.)