Question

A food safety guideline is that the mercury in fish should be below 1 part per million​ (ppm). Listed below are the amounts of mercury​ (ppm) found in tuna sushi sampled at different stores in a major city. Construct a 99​%confidence interval estimate of the mean amount of mercury in the population. Does it appear that there is too much mercury in tuna​ sushi?

0.60 0.82 0.11 0.87 1.27 0.57 0.85

Answer 1

99% confidence interval is given by

Lower CI=(Xbar-t*s/sqrt(n))

Upper CI=(Xbar+t*s/sqrt(n))

sample data=0.60 0.82 0.11 0.87 1.27 0.57 0.85

Xbar=0.7271

s=0.356

99% Confidence Interval

Lower CI=(Xbar-t*s/sqrt(n))=(0.7271-(3.707)*0.356/sqrt(7))

                                        =0.7271-0.4987

                                        =0.2283

Upper CI=(Xbar+t*s/sqrt(n))=(0.7271+(3.707)*0.356/sqrt(7))

                                          =0.7271+0.4987

                                        =1.2258

99​%confidence interval=(0.2283,1.2258)