#### Answer

survival rate = $74.8\%$

#### Work Step by Step

RECALL:
$R=\dfrac{P}{B}$ where $P$=part or amount (percentage), $B$=base, and $R$=rate
The given problem has:
$B= 250$ mallards
$P= 187$ mallards
Use the formula above to find the survival rate:
$=\dfrac{187}{250}
\\=0.748
\\=0.748 \times 100\%
\\=74.8\%$