The table displays the number of butterflies collected in a sample over three years. What inferences can be made from the sample
s taken on butterfly populations? Select three choices. Louden County Butterfly Count Year 1 Year 2 Year 3 Zebra Swallowtail 21 Zebra Swallowtail 10 Zebra Swallowtail 10 Viceroy 3 Viceroy 4 Viceroy 3 Painted Lady 2 Painted Lady 0 Painted Lady 16 Monarch 82 Monarch 52 Monarch 57 The average number of monarchs over all three samples is less than the number of monarchs counted in year 3. The Viceroy population remained fairly steady over the three years recorded. The average number of Zebra Swallowtails over all three samples will be less than the number recorded in year 1. If a population is increasing over time, the average will be less than the most recent count. There was a mistake in the sample for year 3 as the Painted Ladies were extinct in year 2.
<span>p1=44/88=.50; p2=57/85=.67.
Under the null hypothesis of no difference, we pool the data to estimate the
common p of (44+57)/(88+85)=.584.
The test statistic is (.67-.50)/sqrt[(.584)(1-.584)(1/88 + 1/85)]=2.268 (which is stat sig. at a .095 level).</span>
