Question

attend to precision (see example 6)

1. the table shows the number of species in the united

states listed as endangered and threatened.
find the probability that a randomly selected
endangered species is a bird,

	endangered	threatened
birds	80	16
other	318	142

b) find the probability that a randomly selected mammal is endangered.

Explanation:

Part (a) - Probability endangered species is a bird

Step1: Find total endangered species

Sum endangered mammals, birds, and other: \( 70 + 80 + 318 = 468 \)

Step2: Find endangered birds

Endangered birds = \( 80 \)

Step3: Calculate probability

Probability = \( \frac{\text{Endangered Birds}}{\text{Total Endangered}} = \frac{80}{468} = \frac{20}{117} \approx 0.171 \)

Part (b) - Probability mammal is endangered

Step1: Find total mammals

Sum endangered and threatened mammals: \( 70 + 16 = 86 \)

Step2: Find endangered mammals

Endangered mammals = \( 70 \)

Step3: Calculate probability

Probability = \( \frac{\text{Endangered Mammals}}{\text{Total Mammals}} = \frac{70}{86} = \frac{35}{43} \approx 0.814 \)

Answer:

a) \(\boldsymbol{\frac{20}{117}}\) (or approximately \(0.171\))
b) \(\boldsymbol{\frac{35}{43}}\) (or approximately \(0.814\))