Of 100 students surveyed, 25 said they would vote for Jen for class
president. If 2,000 students voted
in the school's election, about how
many votes should Jen receive?
A 25
B 100
C 500
D 1,900

a is the correct

ii6tyhj7 juj3yyj333ju jmyhthhtk7h jg hajj jiijh

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