In addition to the quantitative variable pesticide concentration, the researchers also report whether or not the pesticide

Question:

In addition to the quantitative variable pesticide concentration, the researchers also report whether or not the pesticide was detected in the urine (at standard detection levels). Before the participants started eating organic, 111 of the 240 measurements (combining all pesticides and people) yielded a positive pesticide detection. While eating organic, only 24 of the 240 measurements resulted in a positive pesticide detection.

(a) Calculate the sample difference in proportions: proportion of measurements resulting in pesticide detection while eating non-organic minus proportion of measurements resulting in pesticide detection while eating organic.

(b) Figure 3.33 gives a bootstrap distribution for the difference in proportions, based on 1000 simulated bootstrap samples. Approximate a 98\% confidence interval.

(c) Interpret this interval in context.

Pertain to a 2015 study which took a Swedish family that ate a conventional diet (non-organic), and then had them eat only organic for two weeks. Pesticide concentrations for several different pesticides were measured in \(\mu \mathrm{g} / \mathrm{g}\) creatinine by testing morning urine. Multiple measurements were taken for each person before the switch to organic foods, and then again after participants had been eating organic for at least one week. The results are pretty compelling, and are summarized in a short video which as of this writing has had over 30 million views online. The data are visualized in Figure 3.31 for eight different detected pesticides, and can be found in OrganicEffect. How do pesticide levels in the body differ after eating organic versus non-organic?

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