Yesterday there were b milligrams of bacteria in a lab experiment. today there are b to the second power milligrams of bacteria. if there are 400 milligrams today how many milligrams of bacteria were there yesterday?

You would do the square root of B since you squared B to find it today so it'd be 20 milligrams of bacteria in the experiment yesterday.

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

my guess would be b and d, but i didn’t actually get out the pen and paper. lol