Stacia bought an unlocked iPhone for $289. The tax was 8.5%. What was the total cost of the phone? How did you arrive at your answer?

$313.57

Step-by-step explanation:

We know tax is added onto what the purchasing price of a good is. Therefore, you take the $289 and add on 8.5%, which is written as 289 * 1.085. You should get $313.57.

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