Question

This desbon. 7 of 21 15 completely This Test: 21 pts possit The probability that a randomly selected 2-year-old male salamander wil live to be 3 years old is 0.90036 (a) What is the probability that two randomly selected 2-year-old male salamanders will live to be 3 years old? What is the probability that eight randomly selected 2 year old male salamanders will live to be 3 years old? What is the probability that at least one of eight randomly selected 2-year-old male salamanders will not live to be 3 years old? Would it be unusual it at least one of eight randomly selected 2-year-old male salamanders did not live to be The probability that two randomly wlected 2-year-old male salamanders will live to be 3 years old is Round to five decimal pended) by The probability that eight randomly selected 2 year-old male salamanders will live to be 3 years Round to five decimal pieces as needed) to the probability that at least one of eight randomly selected 2-year-old male anders wil net ive to be 3 years old Wo be one of a randomly selected 2-year-old male samaders did notive to be 3 years old? because the probably of this becoming 0.05

Answer 1

P(A) = n(E)/n(S)

Where P(A) is the probability of an event A

n(E) is the number of favorable outcomes

n(S) is the total number of events in the sample space.  

a)

The probability of 2-year-old male salamanders living up to 3 years is 0.99036.

Probabilit of 2 randomly selected 2-year-old male salamanders living up to 3 years = 0.99036 * 0.99036 = 0.980813

b)

Probability of 8 randomly selected 2-year-old male salamanders living up to 3 years = 0.99036 * 0.99036 * 0.99036 * 0.99036 * 0.99036 * 0.99036 * 0.99036 * 0.99036 = 0.925432

c)

The probability of at least one of the 8 randomly selected 2-year-old salamanders not living is same means probability of 1, 2, 3, 4, 5, 6, 7 or 8 randomly selected 2-year-old salamanders not living, which is same as subtracting the probability of all the salamanders living from 1.

probability of at least one of the 8 randomly selected 2-year-old salamanders not living = 1 - Probability of 8 randomly selected 2-year-old male salamanders living up to 3 years

probability of at least one of the 8 randomly selected 2-year-old salamanders not living = 1 - 0.925432 = 0.074568

No, it is not unusual as it is more than 0.05.