26. For each of the following situations (a) through (h), select the most appropriate sampling or experimental study design from the list below. Explain your choices. Completely random sampling Completely randomized experiment Systematic sampling Matched-pairs experiment Stratified sampling Block design experiment Natural experiment Factorial design experiment ace of porthern spotted d. A toxicologist wants to determine if a combination of two estrogen-like pesticides have a greater effect on reproductive development in mammals than either one separately. e. A toxicologist wants to determine if a new estrogen-like pesticide affects reproductive system development in mammals. He will expose laboratory rats to the pesticide, but is concerned that the pesticide may have differential effects on male vs. female rats. f. Some toxicologists criticize experiments on the effects of estrogen-like pesticides that use rats because rats have a different estrogen physiology than that of humans. These toxicologists want to obtain data for the effects on humans of exposure to estrogen-like pesticides, singly and in combination. How could these data be obtained without a serious breach of ethics? g. A health and nutrition researcher wants to determine if people who are on a calorie- restriction diet and do an hour of aerobic exercise three days per week lose more weight than people who just restrict caloric intake, people who just exercise, and people who do neither