Find the Mean 15 , 20 , 30 , 40 , 45

$15$ , $20$ , $30$ , $40$ , $45$

Step 1

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

$\frac{15 + 20 + 30 + 40 + 45}{5}$

Step 2

Cancel the common factor of $15 + 20 + 30 + 40 + 45$ and $5$ .

Factor $5$ out of $15$ .

$\frac{5 \cdot 3 + 20 + 30 + 40 + 45}{5}$

Factor $5$ out of $20$ .

$\frac{5 \cdot 3 + 5 \cdot 4 + 30 + 40 + 45}{5}$

Factor $5$ out of $5 \cdot 3 + 5 \cdot 4$ .

$\frac{5 \cdot (3 + 4) + 30 + 40 + 45}{5}$

Factor $5$ out of $30$ .

$\frac{5 \cdot (3 + 4) + 5 \cdot 6 + 40 + 45}{5}$

Factor $5$ out of $5 \cdot (3 + 4) + 5 (6)$ .

$\frac{5 \cdot (3 + 4 + 6) + 40 + 45}{5}$

Factor $5$ out of $40$ .

$\frac{5 \cdot (3 + 4 + 6) + 5 \cdot 8 + 45}{5}$

Factor $5$ out of $5 \cdot (3 + 4 + 6) + 5 (8)$ .

$\frac{5 \cdot (3 + 4 + 6 + 8) + 45}{5}$

Factor $5$ out of $45$ .

$\frac{5 \cdot (3 + 4 + 6 + 8) + 5 \cdot 9}{5}$

Factor $5$ out of $5 \cdot (3 + 4 + 6 + 8) + 5 (9)$ .

$\frac{5 \cdot (3 + 4 + 6 + 8 + 9)}{5}$

Cancel the common factors.

Factor $5$ out of $5$ .

$\frac{5 \cdot (3 + 4 + 6 + 8 + 9)}{5 (1)}$

Cancel the common factor.

$\frac{5 \cdot (3 + 4 + 6 + 8 + 9)}{5 \cdot 1}$

Rewrite the expression.

$\frac{3 + 4 + 6 + 8 + 9}{1}$

Divide $3 + 4 + 6 + 8 + 9$ by $1$ .

$3 + 4 + 6 + 8 + 9$

Step 3

Simplify by adding numbers.

Add $3$ and $4$ .

$7 + 6 + 8 + 9$

Add $7$ and $6$ .

$13 + 8 + 9$

Add $13$ and $8$ .

$21 + 9$

Add $21$ and $9$ .

$30$