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