Me with this problem fractions 7th grade me is the answer b check

What is the number 321,000,000 in scientific notation? also what is the number? ?

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

Eric drove 275 miles in 5 hours. at the same rate how long would it take him to drive 495 miles?