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?

0.59 , 0.72 , 0.10 , 0.92 , 1.23 , 0.57 , 0.84

What is the confidence interval estimate of the population mean μ​?

Answer 1

From given data,

Sample mean = 0.71

Sample standard deviation S = 0.3506

t critical value at 6 df with 0.01 level confidence = 3.707

99% confidence interval for is

- t * S / sqrt(n) < < + t * S / sqrt(n)

0.71 - 3.707 * 0.3506 / sqrt(7) < < 0.71 + 3.707 * 0.3506 / sqrt(7)

0.2188 < < 1.2012

99% CI is ( 0.2188 , 1.2012 )