Let's solve this problem step-by-step!
\[ 3.5 = 3\frac{1}{2} = \frac{7}{2} = \frac{7 \times 30}{2 \times 30} = \frac{210}{60} \]
\[ 4\frac{2}{3} = \frac{14}{3} = \frac{14 \times 20}{3 \times 20} = \frac{280}{60} \]
\[ 2\frac{2}{15} = \frac{32}{15} = \frac{32 \times 4}{15 \times 4} = \frac{128}{60} \]
\[ \frac{210}{60} + \frac{280}{60} + \frac{128}{60} = \frac{618}{60} = \frac{103}{10} \]
\[ 1\frac{1}{20} = \frac{21}{20} \]
\[ 4.1 = 4\frac{1}{10} = \frac{41}{10} = \frac{41 \times 2}{10 \times 2} = \frac{82}{20} \]
\[ \frac{21}{20} + \frac{82}{20} = \frac{103}{20} \]
\[ \frac{103}{10} : \frac{103}{20} = \frac{103}{10} \times \frac{20}{103} = \frac{20}{10} = 2 \]
Answer: 2