The probability that Shania is on time for school is . Find the probability that Shania arrives on time for school for the next 5 days. Express your answer as a percent, to the nearest tenth of a percent.

Question

anonymous · Answer

P(Shania arrives on time for school for the next 5 days)
= P(arrived on time on first day) x P(arrived on time on second day) x  P(arrived on time on third day) x  P(arrived on time on fourth day) x  P(arrived on time on fifth day)
= (1/2) x (1/2) x (1/2) x (1/2) x (1/2)
=  (1/2)^5
= ?

mathmate · Answer

p=probability that she arrives on time for one day.
for two days, it's p^2
...

anonymous · Answer

Out of 1,100 discs tested, 13 are defective. Estimate the number of defective discs in a batch of 41,000.

mathmate · Answer

I would just use the expected value, such as np.