Finding the Fourth Proportional to 1,320.30, 1,818.86 and 1,057.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.30 : 1,818.86 = 1,057.86 : x
2. Step 2: Convert to fraction form
   1,320.30/1,818.86 = 1,057.86/x
3. Step 3: Cross multiply
   1,320.30x = 1,818.86 × 1,057.86
4. Step 4: Simplify right side
   1,320.30x = 1,924,093.95
5. Step 5: Solve for x
   x = 1,924,093.95/1,320.30
6. Step 6: Final answer
   x = 1,457.32