Rosa and Clarice are making sandwiches for all the students in their class and their teacher. There are 23 students in their class. Each loaf of bread has 16 slices. They don’t want to use the slices on the ends of the bread, because most students don’t like them. If they make 1 sandwich for each student and for the teacher, how many loaves of bread will they need? Show all your work. (Hint: Don't forget to add the teacher. Also remember you can't buy half a loaf of bread, so how many whole loaves?) This is so hard!

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560