Calculate the mean of each data set below. Can you find any shortcuts that allow you to find the mean without having to do much calculation?  

1. $6$, $10$, $6$, $10$

   Hint (a):

   $\text{Mean}=\frac{6+10+6+10}{4}$

   More Help (a):

   What is the mean of $6$ and $10$? Is it different from the mean of $6$, $10$, $6$, and $10$?

   Answer (a):

   $8$

2. $11$, $12$, $12$, $13$, $12$

   Hint (b):

   What is the mean of $11$ and $13$? How does this help you find the mean more quickly?

3. $0$, $5$, $4$, $8$, $0$, $7$

   Step 1 (c):

   $\frac{0+5+4+8+0+7}{6}$

   Step 2 (c):

   $\frac{9+15}{6}$

   Step 3 (c):

   $\frac{24}{6}$

   Answer (c):

   $4$