Please give me a full correct answer WITH EXPLANATION!!! An ecological group suspects dolphins are consuming dangerous levels of arsenic in a region of the world. Dangerous levels of arsenic are classified when they reach beyond 7.0 parts per million. A random sample of 28 dolphins in the region were tested and the data is shown in the stemplot.

Stemplot for Arsenic Levels. 2|4; 2|; 3|2 3; 3|6 7 9; 4|0 1 3; 4|5 7 7; 5|0 1 1 4 4; 5|7 8; 6|3 4; 6|6; 7|0 1 3; 7|5 6 7.

Key: 2|4 = 2.4 parts per million

Part A: What proportion of the dolphins in the sample have dangerous levels of arsenic in their systems? (4 points)

Part B: Construct and interpret a 99% confidence interval for the mean arsenic levels of the dolphins if the sample of 28 dolphins has a mean arsenic level of 5.26 parts per million and standard deviation of 1.49 parts per million. (6 points)