Finding the Fourth Proportional to 1,018.55, 1,404.37 and 860.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.55 : 1,404.37 = 860.91 : x
2. Step 2: Convert to fraction form
   1,018.55/1,404.37 = 860.91/x
3. Step 3: Cross multiply
   1,018.55x = 1,404.37 × 860.91
4. Step 4: Simplify right side
   1,018.55x = 1,209,031.99
5. Step 5: Solve for x
   x = 1,209,031.99/1,018.55
6. Step 6: Final answer
   x = 1,187.01