The U.S. Census Bureau reported 77% of the U.S population had internet access in 2009. Choosing 3 random individuals find the probability that
a. none of the 3 inidivuals has internet
b. all of the individuals have internet access
c. at least 1 of the 3 individuals has internet access
.77 have it so .23 don't
None of the 3 have it.
(.23)^3
All have it.
(.77)^3
At least 1 has it means that 1, 2 or 3 have it. It is easier to do the problem in the reverse. If at least 1 has it, the opposite would be none have it. (.23^3)
1 - (.23)^3