20) Find the length of a side of a square with a
diagonal length of 100 cm.

about 7.0710678cm

Step-by-step explanation:

it's a square so the sides are equal.

the diagonal is 100cm

This makes a right triangle with two sides

since the sides are equal, they both are equal to the square root of 50, which is half of 100

the square root of 50 is about 7.0710678cm

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