Finding the Fourth Proportional to 665,870.62, 999,516.71 and 286,978.34

Step by Step Solution

1. Step 1: Write the proportion equation
   665,870.62 : 999,516.71 = 286,978.34 : x
2. Step 2: Convert to fraction form
   665,870.62/999,516.71 = 286,978.34/x
3. Step 3: Cross multiply
   665,870.62x = 999,516.71 × 286,978.34
4. Step 4: Simplify right side
   665,870.62x = 286,839,646,238.06
5. Step 5: Solve for x
   x = 286,839,646,238.06/665,870.62
6. Step 6: Final answer
   x = 430,773.84