Answer:
(24,13)
Step-by-step explanation:
24 is Sarah's age.
13 is Mike's age.
System:

I hope this helped!
Answer:
D, the observed frequency of landing heads up gets closer to the expected frequency based on the probability of the coin landing heads up.
Step-by-step explanation:
As of now, the observed frequency states that the coin will land on heads 4/12 times. The expected frequency states that the coin will land on heads 50% of the time, or 6/12 times. As the number of trials increases, the observed frequency will get closer to the expected frequency.
Use the formula i=prt, where i is the interest earned, p is the principal, r is the rate (as a decimal fraction) and t is the elapsed time, in years.
Here i = $72 = $1200 r (9/12) (9 months is 9/12, or 3/4, of 1 year)
Reducing,
$72 = $900r
Solving for r, r=0.08, or 8 percent per year.