Question

The numbers of endangered species for several groups are listed here. Mammals Birds Reptiles Amphibians United States 63 78 14 10 Foreign 251 175 64 8 If one endangered species is selected at random, find the probability that it is a. Found in the United States and is a bird b. Foreign or a mammal c. Warm-blooded

Answer 1

The probability that an endangered species is found in the United States and is a bird is approximately 0.1194. The probability that an endangered species is foreign or a mammal is approximately 0.4806. The probability that an endangered species is warm-blooded is approximately 0.2527.

Step-by-step explanation:

To find the probability that an endangered species is found in the United States and is a bird, we need to find the number of endangered species that meet both criteria and divide it by the total number of endangered species. From the given information, there are 78 bird species in the United States. So the probability is:

Probability = Number of endangered species in the United States that are birds / Total number of endangered species

Probability = 78 / (63 + 78 + 14 + 10 + 251 + 175 + 64 + 8) = 78 / 653 = 0.1194 (rounded to four decimal places).

Therefore, the probability that an endangered species is found in the United States and is a bird is approximately 0.1194.

To find the probability that an endangered species is foreign or a mammal, we need to find the number of endangered species that meet either criteria and divide it by the total number of endangered species. From the given information, there are 251 foreign species and 63 mammal species. So the probability is:

Probability = Number of endangered species that are foreign or mammals / Total number of endangered species

Probability = (251 + 63) / (63 + 78 + 14 + 10 + 251 + 175 + 64 + 8) = 314 / 653 = 0.4806 (rounded to four decimal places).

Therefore, the probability that an endangered species is foreign or a mammal is approximately 0.4806.

To find the probability that an endangered species is warm-blooded, we need to find the number of endangered species that are warm-blooded and divide it by the total number of endangered species. From the given information, all mammals are warm-blooded. So the probability is:

Probability = Number of endangered species that are warm-blooded / Total number of endangered species

Probability = (63 + 78 + 14 + 10) / (63 + 78 + 14 + 10 + 251 + 175 + 64 + 8) = 165 / 653 = 0.2527 (rounded to four decimal places).

Therefore, the probability that an endangered species is warm-blooded is approximately 0.2527.

Answer 2

The probability of randomly selecting an endangered species that is a US bird is 0.1176, foreign or a mammal is 0.8410, and warm-blooded is 0.8446.

Step-by-step explanation:

To calculate the probability of the given scenarios, we need to first calculate the total number of endangered species by adding the given numbers:

• 
  
• Mammals in the US: 63
• 
  
• Birds in the US: 78
• 
  
• Reptiles in the US: 14
• 
  
• Amphibians in the US: 10
• 
  
• Mammals foreign: 251
• 
  
• Birds foreign: 175
• 
  
• Reptiles foreign: 64
• 
  
• Amphibians foreign: 8

Total = 63 + 78 + 14 + 10 + 251 + 175 + 64 + 8 = 663

a. The probability that an endangered species selected at random is found in the United States and is a bird is:

P(US Bird) = Number of US Birds / Total Number of Species = 78 / 663 = 0.1176 (rounded to four decimal places)

b. The probability that an endangered species is foreign or a mammal (combining both US and foreign mammals) is:

P(Foreign or Mammal) = (Number of Foreign Species + Number of Mammals) / Total Number of Species = (251 + 175 + 64 + 8 + 63) / 663 = 0.8410 (rounded to four decimal places)

c. Warm-blooded animals include birds and mammals. Calculating the probability that an endangered species is warm-blooded:

P(Warm-blooded) = (Number of Birds + Number of Mammals) / Total Number of Species = (78 + 251 + 63 + 175) / 663 = 0.8446 (rounded to four decimal places)