Find the standard form of the equation of the parabola with a focus at (-7, 0) and a directrix at x = 7.

a) x = negative 1 divided by 28y^2
b) -28y = x^2
c) y^2 = -14x
d) y = negative 1 divided by 28x^2

x = 1/(4p)*y^2

x = 1/(4*-7)*y^2

x = -1/28*y^2

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