Lenny asked five of his friends how many pencils they had in their pencil bag. his teacher said students never bring pencils to class. which of the following statement could he use to convince her that she is wrong based on his graph?

a.

most students brought 6 pencils to class.
b.

the mean number of pencils that these five students brought to class is 6 pencils. c.

the mean number of pencils that these five students brought to class is 10 pencils.
d.

the mean number of pencils that these five students brought to class is 4 pencils.

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