A local weather forcaster is accurate 85% of the time when predicting precipitation for the day. What is the probability that she will make correct precipitation predictions 4 days in a row?

Question

unklerhaukus · Answer

$$P=(85 \% )^ 4$$

anonymous · Answer

Okay, thanks! I understand it now. Is it 0.85 * 0.85 * 0.85 * 0.85, right?

unklerhaukus · Answer

yep
~52%

anonymous · Answer

That's what I just got, too.

anonymous · Answer

I have another one: how many different ways can you arrange 7 books on a shelf?

unklerhaukus · Answer

the first book can go in seven possible places,
the second can go in 6 possible places
the third can go in 5 possible places
......
$$7!=7\times6\times5\times 4\times 3\times 2\times1=5040$$