Question

Based on a poll, among adults who regret getting tattoos, 19% say that they were too young when they got their tattoos. Assume that eight 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 tattos.

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. I we randomly select eight adults, is 1 a significantly low number who say that they were too young to get tattoos?

Answer 1

Binomial distribution: P(x) = nCx p^x q^n-x

P(a person say that he or she was too young when they got the tattoo), p = 0.19

q = 1 - 0.19 = 0.81

Sample size, n = 8

a) P(none of the selected adults say that they were too young to get tattoos), P(0) = 0.81⁸

= 0.1853

b) P(exactly one of the selected adults says that he or she was too young to get tattoos), P(1) = 8 x 0.19 x 0.81⁷

= 0.3477

c) P(the number of selected adults saying they were too young is 0 or 1) = 0.1853 + 0.3477

= 0.5330

d) A number is significantly low or high if the probability of occurrence is less than 0.05. The probability that the number of selected adults saying they were too young is less than or equal to 1 is greater than 0.05. Therefore, 1 is not a significantly low number who say that they were too young to get tattoos.