Answer: 0.3439
Step-by-step explanation:
Total number of digits : 10
The number of digits except zero =9
The probability of selecting non-zero number :-
[tex]\dfrac{9}{10}=0.9[/tex]
Then, the probability that one such phone number , the last four digits do not include any zero:-
[tex]\text{P(no zero )}=(0.9)^4[/tex]
Then , the probability that for one such phone​ number, the last four digits include at least one 0:-
[tex]\text{P(at-least one zero )}=1-(0.9)^4=0.3439[/tex]
Hence, the probability that for one such phone​ number, the last four digits include at least one 0 is 0.3439 .