average of $4.50, $3.50, $5.50 and $2.90

You can find the answer by adding all the values and dividing by the number of values (in this case 4)

So the answer is

$${\frac{\left({\mathtt{4.5}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3.5}}{\mathtt{\,\small\textbf+\,}}{\mathtt{5.5}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2.9}}\right)}{{\mathtt{4}}}} = {\frac{{\mathtt{41}}}{{\mathtt{10}}}} = {\mathtt{4.1}}$$

So your answer is $4.10

Reinout 

You don't want your answer now?

then I'll give it later...

$$\\\$4.50+ \$3.50+ \$5.50 +\$2.90 = \$16.40\\ \\ \dfrac{\$16.40}{4}=\$4.10\\ \\ \text{The average of }\; \$4.50, \$3.50, \$5.50 \text{ and } \$2.90 \text{ is } \$4.10$$

I bet that went over a head Reinout!  lol

i guess its $4.1 .......... maybe.......im not that sure.......because im good at math

lol... Good at maths....