In a survey of a rare clumped species, the study area is divided into two strata, with N1 = 60 units in the first stratum and N2 = 50 units in the other. Initial simple random samples of sizes n1 = 3 and n2 = 2 are used. Whenever one or more of the animals are found, adjacent units are added as in text examples. In stratum 1, the first initial sample unit had one animal in it; no further animals were found in adjacent units. The second sample unit had no animals. The third sample unit had two animals; of the adjacent units added within that stratum, the only one with animals had three. That unit was adjacent to the stratum boundary, so adding its adjacent units resulted in crossing the stratum boundary and discovering three more units, with two, one, and one animals,

respectively. The two initial units selected in stratum 2 each had no animals. Estimate the number of animals in the study region using ˆμ0 and ˆμ1. Estimate the variance of the estimator.