Finding the Fourth Proportional to 2,207.61, 3,312.17 and 1,111.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,207.61 : 3,312.17 = 1,111.07 : x
2. Step 2: Convert to fraction form
   2,207.61/3,312.17 = 1,111.07/x
3. Step 3: Cross multiply
   2,207.61x = 3,312.17 × 1,111.07
4. Step 4: Simplify right side
   2,207.61x = 3,680,052.72
5. Step 5: Solve for x
   x = 3,680,052.72/2,207.61
6. Step 6: Final answer
   x = 1,666.98