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?

0.52

  

0.70

  

0.10

  

0.99

  

1.26

  

0.54

  

0.91

What is the confidence interval estimate of the population mean

mu

​?

nothing

ppmless than

muless thannothing

ppm

​(Round to three decimal places as​ needed.)

Does it appear that there is too much mercury in tuna​ sushi?

A.

​No, because it is possible that the mean is not greater than 1 ppm.​ Also, at least one of the sample values is less than 1​ ppm, so at least some of the fish are safe.

B.

​No, because it is not possible that the mean is greater than 1 ppm.​ Also, at least one of the sample values is less than 1​ ppm, so at least some of the fish are safe.

C.

​Yes, because it is possible that the mean is not greater than 1 ppm.​ Also, at least one of the sample values exceeds 1​ ppm, so at least some of the fish have too much mercury.

D.

​Yes, because it is possible that the mean is greater than 1 ppm.​ Also, at least one of the sample values exceeds 1​ ppm, so at least some of the fish have too much mercury.

Answer 1

	Data
	0.52
	0.7
	0.1
	0.99
	1.26
	0.54
	0.91
Mean	0.717143	AVERAGE()
SD	0.378097	STDEV()
n	7

99% CI

α=	0.01
df	6	n-1

CI
tc	3.707428	T.INV.2T(alpha,df)
Upper	1.246922	X bar + tc*(S/SQRT(n))
Lower	0.187278	X bar - tc*(S/SQRT(n))

99% CI = (0.187,1.247)

​Yes, because it is possible that the mean is greater than 1 ppm.​ Also, at least one of the sample values exceeds 1​ ppm, so at least some of the fish have too much mercury.