In a wildlife survey, an area of desert land was divided into 1000 squares, or "quadrats," a simple random sample of 50 of which were surveyed In each sur- veyed quadrat, the number of birds, Y, and the area covered by vegetation, X, were determined. It was found that

a. Estimate the ratio of the avenge number of birds per quadrat to the average vegetation cover per quadrat.

b. Estimate the standard error of your estimate and find an approximate 90% confidence interval for the population average.

c. Estimate the total number of birds and find an approximate 95% confidence interval for the population total.

d. Suppose that from an aerial survey, the total area covered by vegetation could easily be determined. How could this information be used to provide another estimate of the number of birds? Would you expect this estimate to be better than or worse than that found in part (c)?

XX = 3000 XY = 150 2 x = 225,000 X Y = 650 XX,Y = 11,000