Finding the Fourth Proportional to 1,521.12, 2,099.72 and 1,312.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,521.12 : 2,099.72 = 1,312.12 : x
2. Step 2: Convert to fraction form
   1,521.12/2,099.72 = 1,312.12/x
3. Step 3: Cross multiply
   1,521.12x = 2,099.72 × 1,312.12
4. Step 4: Simplify right side
   1,521.12x = 2,755,084.61
5. Step 5: Solve for x
   x = 2,755,084.61/1,521.12
6. Step 6: Final answer
   x = 1,811.22