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1. A forced-choice design is often used to compare the attractiveness of pheromones to insects. A Y-tube is used. The pheromone is place on one branch; the control on the second branch; and the insect on the third branch. The insect then chooses one of the two branches. Suppose that28 of 70 insects choose the pheromone branch. The 95% plus-four confidence interval for the proportion of the population that prefers the pheromone branch is:

0.39 0.07.

0.39 0.06.

0.41 0.06.

0.41 0.16.