Find the Mean 1 , 1 , 3 , 3 , 5 , 5 , 6 , 7 , 9 , 9 , 9 , 10 , 10

$1$ , $1$ , $3$ , $3$ , $5$ , $5$ , $6$ , $7$ , $9$ , $9$ , $9$ , $10$ , $10$

The mean of a set of numbers is the sum divided by the number of terms.

$\frac{1 + 1 + 3 + 3 + 5 + 5 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Simplify the numerator.

Add $1$ and $1$ .

$\frac{2 + 3 + 3 + 5 + 5 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $2$ and $3$ .

$\frac{5 + 3 + 5 + 5 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $5$ and $3$ .

$\frac{8 + 5 + 5 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $8$ and $5$ .

$\frac{13 + 5 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $13$ and $5$ .

$\frac{18 + 6 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $18$ and $6$ .

$\frac{24 + 7 + 9 + 9 + 9 + 10 + 10}{13}$

Add $24$ and $7$ .

$\frac{31 + 9 + 9 + 9 + 10 + 10}{13}$

Add $31$ and $9$ .

$\frac{40 + 9 + 9 + 10 + 10}{13}$

Add $40$ and $9$ .

$\frac{49 + 9 + 10 + 10}{13}$

Add $49$ and $9$ .

$\frac{58 + 10 + 10}{13}$

Add $58$ and $10$ .

$\frac{68 + 10}{13}$

Add $68$ and $10$ .

$\frac{78}{13}$

Divide $78$ by $13$ .

$6$