An ecological group suspects tuna are consuming dangerous levels of copper in a region of the world. Dangerous levels of copper are classified when they reach beyond 5.7 ppm. A random sample of 21 tuners in the region were tested in the data shown in the stem plot.

Copper Levels

2 | 0

2| 3|1

3|5 7 8

4| 0 1

4| 5 6 7 8

5| 0 2 3 3

5| 6 8 9

6| 3 4

6| 5 Part A what portion of a tuna in the sample have dangerous levels of copper in their systems? Part B construction interpret a 98% confidence interval for the mean copper levels of a tuna and if the sample of 21 to know has a mean copper level of 4.77 ppm in standard deviation of 1.16 ppm