Question

mascot survey
sample 1\t\tsample 2
ducks\t12\tducks\t8
grizzlies\t24\tgrizzlies\t30
lions\t20\tlions\t22
silverbacks\t16\tsilverbacks\t12
$\frac{21}{72} = \frac{x}{480}$
$\frac{72}{21} = \frac{x}{480}$
$\frac{42}{72} = \frac{x}{480}$
$\frac{20}{22} = \frac{x}{480}$

Explanation:

Step1: Calculate total of Sample 1

$12 + 24 + 20 + 16 = 72$

Step2: Calculate total of Sample 2

$8 + 30 + 22 + 12 = 72$

Step3: Sum Ducks from both samples

$12 + 8 = 20$

Step4: Sum Lions from both samples

$20 + 22 = 42$

Step5: Match to population proportion

We use combined sample proportion of Lions ($\frac{42}{72}$) to estimate population count $x$ out of 480: $\frac{42}{72} = \frac{x}{480}$

Answer:

$\frac{42}{72} = \frac{x}{480}$