Finding the Fourth Proportional to 1,385.61, 1,911.72 and 1,316.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.61 : 1,911.72 = 1,316.34 : x
2. Step 2: Convert to fraction form
   1,385.61/1,911.72 = 1,316.34/x
3. Step 3: Cross multiply
   1,385.61x = 1,911.72 × 1,316.34
4. Step 4: Simplify right side
   1,385.61x = 2,516,473.50
5. Step 5: Solve for x
   x = 2,516,473.50/1,385.61
6. Step 6: Final answer
   x = 1,816.15