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 95​% confidence interval estimate of the mean amount of mercury in the population. Does it appear that there is too much mercury in tuna​ sushi? 0.61  0.80  0.09  0.93  1.27  0.50  0.90 What is the confidence interval estimate of the population mean u?

? ppm < u < ? ppm

Answer 1

Solution:

Confidence interval for Population mean is given as below:

Confidence interval = Xbar ± t*S/sqrt(n)

From given data, we have

Xbar = 0.728571429

S = 0.374674462

n = 7

df = n – 1 = 6

Confidence level = 95%

Critical t value = 2.4469

(by using t-table)

Confidence interval = Xbar ± t*S/sqrt(n)

Confidence interval = 0.728571429 ± 2.4469*0.374674462/sqrt(7)

Confidence interval = 0.728571429 ± 0.3465

Lower limit = 0.728571429 - 0.3465 = 0.3821

Upper limit = 0.728571429 + 0.3465 = 1.0751

Confidence interval = (0.3821, 1.0751)

0.3821 ppm < µ < 1.0751 ppm