When I put it in my calculator I got d=5
The answer to your question is 134:)
Its $800 because to find interest u can use the formula I=PRT p is principal which is 500 times r which is rate-15/100(=15%) times 4
so the interest is 500×15/100×4=300
then u add 300 to 500 because the interest adds more money to the loan
2a+4(7+5a)
Distribute 4 into 7 and 5a
2a+28+20a
Combine like terms
Final Answer: 22a+28
Solution: We are given below data:

Now to find the mean deviation, we use the below formula:

Where:
represents the summation
X, represents the observation.
represents the mean
N represents the number of observation.


Therefore, the mean deviation is:

= 4