Which of the following correctly describes the variation in the equation r=d/t?

1. r varies inversely with d and jointly with t
2. r varies jointly with t and d.
3. r varies inversely with t and jointly with d.
4. r varies directly with d and inversely with t.

Option 3rd is the right choice.

Step-by-step explanation:

Which of the following correctly describes the variation in the equation r=d/t?

Option 3rd is correct - r varies inversely with t and jointly with d

Inversely related means if the value of one entity increases, the value of second decreases and vice versa.

Here, r = d*1/t

So, we can say r = 1/t, this means r is in an inverse relation to t and direct relation to d.

So, option 3rd is the correct choice.

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