1. The problem asks to round the number $3.967$ to the nearest tenth. 2. Identify the tenths and hundredths place. The tenths place is the first digit after the decimal point, which is $9$. 3. Look at the digit to the right (hundredths place) to decide whether to round up or down. The digit here is $6$. 4. Since $6$ is greater than or equal to $5$, we round the tenths place up by one. 5. Increasing $9$ by $1$ results in $10$, so the units digit increases by $1$, making the number $4.0$. 6. Therefore, $3.967$ rounded to the nearest tenth is $4.0$. **Final answer: $4.0$**