Since A is the midpoint of BC, we can assume BA and AC are equal to each other. 
We also know that BC = BA + AC = 23 + 23 = 46
 
        
                    
             
        
        
        
Answer: Mean = 7.8
               Median = 9
              Mode = 2,9
Step-by-step explanation: <u>Mean</u> is the average value of a data set. Mean from a frequency table is calculated as:

E(X) = 7.8
Mean for the given frequency distribtuion is 7.8.
<u>Median</u> is the central term of a set of numbers. Median in a frequency table is calculated as:
1) Find total number, n:
n = 10 + 9 + 10 + 7 + 3 + 4 + 3 = 46
2) Find position, using: 
 = 23.5
 = 23.5
Median is in the 23.5th position.
3) Find the position by adding frequencies: for this frequency distribution, 23.5th position is 9
Median for this frequency distribution is 9.
<u>Mode</u>  is the number or value associated with the highest frequency.
In this frequency distribution, 2 and 9 points happen 10 times. So, mode is 2 and 9.
Mode for this distribution is 2 and 9.