When Sophia's mom picks her up from school, she is late one third of the time. For
the next 15 days, what is the probability
that she will be late at most three days?

20.92 %.  

Step-by-step explanation:

Add the individual probability of 0, 1, 2, and 3 late days out of 15

P(0 days) = (2/3)15    Notice that I have made P the probability of NOT being late.

P(1 day) = 15(2/3)14(1/3)

Hope this helps!

relating to or denoting a system of numbers and arithmetic based on the number ten, tenth parts, and powers of ten.

it alot will look like this 4.4