Finding the Fourth Proportional to 1,007.18, 1,389.98 and 565.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.18 : 1,389.98 = 565.10 : x
2. Step 2: Convert to fraction form
   1,007.18/1,389.98 = 565.10/x
3. Step 3: Cross multiply
   1,007.18x = 1,389.98 × 565.10
4. Step 4: Simplify right side
   1,007.18x = 785,482.59
5. Step 5: Solve for x
   x = 785,482.59/1,007.18
6. Step 6: Final answer
   x = 779.88