Answer
$12\frac{15}{16} \text{ft}$
Work Step by Step
Add the given lengths to find the total length of the welded piece:.
Total length
$=3\frac{1}{4} + 2\frac{3}{8} + 3\frac{1}{8} + 4\frac{3}{16}
\\=(3+2+3+4) + (\frac{1}{4}+\frac{3}{8}+\frac{1}{8} + \frac{3}{16})
\\=12+ (\frac{1}{4}+\frac{4}{8}+\frac{3}{16})$
Make the fractions similar using their LCD of $16$ to obtain:
Total length
$\\=12+(\frac{4}{16}+\frac{8}{16}+\frac{3}{16})
\\=12+\frac{15}{16}
\\=12\frac{15}{16} \text{ft}$
