Question 1133946
I calculated the sample mean and standard deviation on a graphing calculator.  Because of the small sample size, a t-score should be used.  The t-score for a 99% confidence level with degrees of freedom of 6 (one less than sample size) is 3.71.  This is multiplied by the sample standard deviation which is divided by the sq rt of the sample size.  

The interval is (0.19, 1.31).  This means that there is a good chance that the population mean is above 1 (can be as high as 1.31).  Therefore, there does appear to be evidence that the mercury level is too high.

*[illustration CI_for_mean_solution]