Question

Arsenic-based additives in chicken feed have been banned by the E.U., but are mixed in the diet of about 70% of the 9 billion broiler chickens produced annually in the U.S. Many restaurants and supermarket chains are working to reduce the amount of arsenic in the chicken they sell.

To accomplish this, one chain plans to measure, for each supplier, the amount of arsenic in a random sample of chickens. The chain will cancel its relationship with a supplier if the sample provides sufficient evidence that the average amount of arsenic in chicken provided by the supplier is greater than 80 ppb (parts per billion).

a) The parameter of interest is                            [ Select ]                       ["Single proportion", "Difference in proportions", "Single mean", "Difference in means"]         .

b) The correct null and alternative hypotheses are

Answer 1

a) here we are interested in seeing if the average amount of arsenic in chicken provided by the supplier is greater than 80 ppb (parts per billion).

So here one supplier will be chosen at a time. Then the mean amount of arsenic in chicken provided by the supplier is to be calculated and to be checked if it is more than 80 ppb or not.

Hence, here the parameter of interest is single mean (i.e. the mean content of arsenic in chicken).

Answer: Single mean.

b) here we the interest is to know if the average amount of arsenic in chicken provided by the supplier is greater than 80 ppb (parts per billion) or not.

Let the the population mean amount of arsenic in chicken provided by the supplier be "m" ppb. Here we are interested to test if m is less than or equal to 80 or greater than that. We will accept that m is more than 80 iff we get strong evidence in favour of it. So this will be the alternative hypothesis.

Answer: the hypotheses are:

Null hypothesis is, H:  

Alternative hypothesis is, K: .

Hope the solution helps. Thank you.