The talk-time battery life of a group of cell phone is normally distributed with a mean of 5 hours and a standard deviation of 15 minutes.
b) What percent of the phones have a battery life between 4.5 hours and 5.25
hours? (include 1 decimal place WITHOUT the % sign)

As voters exit the polls, you ask a representative random sample of voters if they voted for a proposition. if the true percentage of voters who vote for the proposition is 63%, what is the probability that, in your sample, exactly 5 do not voted for the proposition before 2 voted for the proposition? the probability is