A safety recommendation to fish farmers, the Environmental Protection Agency (EPA) recommends an organic contaminant level of 0.08 ppm. A researcher test 81 randomly selected farm raised salmon for contaminates and found a mean concentration of the carcinogenic insecticide mirex to be 0.0913 ppm with a standard deviation of 0.0495 ppm. The researcher wishes to perform a significance test to see if sample levels are within the EPA guidelines and construct an appropriate confidence interval. a. For a 95% level of confidence what is the appropriate critical value t* that needs to be used to calculate the margin of error? Determine the value of the critical value using a table or preferred technological tool. Show the degrees of freedom to receive full credit. b. Calculate a 95% confidence interval and explain what it represents within context.
A safety recommendation to fish farmers, the Environmental Protection Agency (EPA)
recommends an organic contaminant level of 0.08 ppm. A researcher test 81 randomly selected
farm raised salmon for contaminates and found a
insecticide mirex to be 0.0913 ppm with a standard deviation of 0.0495 ppm. The researcher
wishes to perform a significance test to see if sample levels are within the EPA guidelines and
construct an appropriate confidence interval.
a. For a 95% level of confidence what is the appropriate critical value t* that needs to be used
to calculate the margin of error? Determine the value of the critical value using a table or
preferred technological tool. Show the degrees of freedom to receive full credit.
b. Calculate a 95% confidence interval and explain what it represents within context.
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