<h3>
Answer: 78.6</h3>
Work Shown:

Multiply across the rows to form a third column. Example: 9*90 = 810 in the first row.

The values in the third column add to 810+1440+1050 = 3300
Divide this over the total number of people which is 9+18+15 = 42
The mean is 3300/42 =78.571 approximately which rounds to 78.6
Answer is in the file below
tinyurl.com/wpazsebu
Answer:
is the logarithmic equation which is equivalent to
.
Step-by-step explanation:
According to the laws of logarithms
,where b=base ,n,x all are positive
It can be written in exponential form such as

Now in the given question x=9 ,b=3 and n=2 such that it will equals to

Hence the logarithmic equation for
is
.
The value of X would be 9