Answer:
The correct statement is:
On average, the height of a garden gnome varies 3.2 inches from the mean of 6 inches.
Step-by-step explanation:
We are given a data of 11 gardens as:
 2   9    1    23    3    7    10    2    10    9     7
Now on removing the outlier i.e. 23 (since it is the very large value as compared to other data points) the entries are as follows:
x         |x-x'|         
2          4               
9          3              
1           5              
3          3               
7           1                
10         4               
2           4              
10          4              
9           3              
7            1               
Now mean of the data is denoted by x' and is calculated as:
 
 
Hence, Mean(x')=6
Now,
∑ |x-x'|=32
Now mean of the absolute deviation is:

This means that , On average, the height of a garden gnome varies 3.2 inches from the mean of 6 inches.