Subjects for the next presidential election poll are contacted using telephone numbers in which the last four digits are randomly selected (with replacement). Find the probability that for one such phone number, the last four digits include at least one 0.
Accepted Solution
A:
Answer:probability at least one zero is 0.3439Step-by-step explanation:given data last four digits = randomly selectedto find out probability that for one such phone number the last four digits include at least one 0.solutionwe know there are total 10 digitso we first find probability of non zero digit i.e.Probability ( non zero ) = 9 /10 = 0.9and now we find probability of none of digit zero only event happen n= 4 time in a row by multiplication rules i.eProbability ( none zero in 4 digit ) = [tex]0.9^{n}[/tex]Probability ( none zero in 4 digit ) = [tex]0.9^{4}[/tex]Probability ( none zero in 4 digit ) = 0.6561so we can say probability at least one zero = 1 - Probability ( none zero in 4 digit ) probability at least one zero = 1 - 0.6561probability at least one zero is 0.3439