Data were collected on random specimens of Yellow fin tuna from 1991 and 2010. For the sample of 231 specimens of Yellowfi n tuna, the average mercury level was found to be 0.354 ppm and the standard deviation of mercury level to be 0.231 ppm. Th e data are not strongly skewed.
a. In the context of this study, explain why it is valid to use the theory-based (t-distribution) approach to find a confidence interval?
b. Use the Theory-Based Inference applet to find and report a 95% confidence interval for the parameter of interest. Also, interpret the interval in the context of the study.