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based on a poll, among adults who regret getting tattoos , 21% say that they wer

ID: 3331525 • Letter: B

Question

based on a poll, among adults who regret getting tattoos , 21% say that they were too young when they got their tattoos. assume that four adults who regret getting tattoos are randomly selected, and find the indicated probability. complete parts (a) through (d) below
(a) find the probability that none of the selected adults say that they were too young to get tattoos
(b) find the probability that exactly one of the selected adults says that he or she was too young to get tattoos
(c) find the probability that the number of selected adults saying they were too young is 0 or 1
(d) if we randomly select four adults, is 1 a significantly low number who say that they were too young to get tattoos? based on a poll, among adults who regret getting tattoos , 21% say that they were too young when they got their tattoos. assume that four adults who regret getting tattoos are randomly selected, and find the indicated probability. complete parts (a) through (d) below
(a) find the probability that none of the selected adults say that they were too young to get tattoos
(b) find the probability that exactly one of the selected adults says that he or she was too young to get tattoos
(c) find the probability that the number of selected adults saying they were too young is 0 or 1
(d) if we randomly select four adults, is 1 a significantly low number who say that they were too young to get tattoos? based on a poll, among adults who regret getting tattoos , 21% say that they were too young when they got their tattoos. assume that four adults who regret getting tattoos are randomly selected, and find the indicated probability. complete parts (a) through (d) below
(a) find the probability that none of the selected adults say that they were too young to get tattoos
(b) find the probability that exactly one of the selected adults says that he or she was too young to get tattoos
(c) find the probability that the number of selected adults saying they were too young is 0 or 1
(d) if we randomly select four adults, is 1 a significantly low number who say that they were too young to get tattoos?

Explanation / Answer

[Note - I will be rounding off all the probabilities to 4 decimal places. Please round it off as per the question demands.]

This will be a binomial distribution with parameters:

n = 4, p = 0.21

q = 1 - p = 1 - 0.21 = 0.79

Hence,

a) P(X = 0) = (0.79)4 = 0.3895

b) P(X = 1) = 4*0.21*(0.79)3 = 0.4142

c) P(X = 0 or X = 1) = 0.3895 + 0.4142 = 0.8037

d) No, 1 is not a significantly low number because the probability of 1 or less is greater than 0.05.