Answer:
Failure of a Single Dell computer in terms of percentage=17%
It means you buy a computer, there is 17% chance that it will be bad Machine and (100-17)%=83% chance that, it will be a good machine.
Probability that if you buy four computers, atleast 1 will fail within a year
[tex]=_{1}^{4}\textrm{P}\times [P(S)]^3\times P(F)+_{2}^{4}\textrm{P}\times [P(S)]^2\times [P(F)]^2+_{3}^{4}\textrm{P}\times P(S)\times [P(F)]^3+_{4}^{4}\textrm{P}\times [P(F)]^4\\\\=4 \times (0.83)^3\times (0.17)+6\times (0.83)^2\times (0.17)^2+4\times (0.83)\times (0.17)^3+1\times (0.17)^4\\\\=0.3881516+0.11945526+0.01631116+0.00083521\\\\=0.52475323[/tex]
=0.53(Approx)
=0.53 × 100
=53%
