Finding the Fourth Proportional to 1,139.29, 1,572.22 and 667.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.29 : 1,572.22 = 667.10 : x
2. Step 2: Convert to fraction form
   1,139.29/1,572.22 = 667.10/x
3. Step 3: Cross multiply
   1,139.29x = 1,572.22 × 667.10
4. Step 4: Simplify right side
   1,139.29x = 1,048,816.77
5. Step 5: Solve for x
   x = 1,048,816.77/1,139.29
6. Step 6: Final answer
   x = 920.59