Answer:
The amount of money in Enid bank account can be written as a linear equation.
Ye = Xe + $4*m
where Ye is the money that Enid has in her account, m is the number of months that have passed since she opened it, and Xe is the initial deposit.
For Jim, the equation is similar:
Yj = Xj + $3*m
where Yj and Xj are similar as above.
Between May 15 and December 31 of the same year, we have 7 months (where i am counting December because the deposit is made in the first day of the month).
Then we have that:
Ye = $72 = Xe + $4*7 = Xe + $28
Xe = $72 - $28 = $44
So in May 15, Enid deposited $44.
For Jim we have:
Yj = $72 = Xj + $3*7 = Xj + $21
Xj = $72 - $21 = $51
So in May 15, Jim deposited $51.
First, start of by saying what the probability of getting a 4 is, which is 1/6.
Now, this means the probability of not getting a 4 is 1-(1/6)=(5/6), since the total probability is 1.
After doing this, you should think about what it means to only get 4 on the last trial, the 4th trial. It means that the probabilities of the 1st, 2nd, and 3rd trial were (5/6) each. The 4th trial had a probability of (1/6). So the probability would be calculated as following: (

=

. You can use a calculator or your computer to find out that the probability is 125/1296.
I hope this was helpful!
AC=2AE ( because diagonal of rhombus bisect each others)
AE=8 cot 53°
AE=6
AC=2 x 6 = 12
Hence, The length of AC is 12