Finding the Fourth Proportional to 1,415.47, 2,120.89 and 866.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.47 : 2,120.89 = 866.50 : x
2. Step 2: Convert to fraction form
   1,415.47/2,120.89 = 866.50/x
3. Step 3: Cross multiply
   1,415.47x = 2,120.89 × 866.50
4. Step 4: Simplify right side
   1,415.47x = 1,837,740.58
5. Step 5: Solve for x
   x = 1,837,740.58/1,415.47
6. Step 6: Final answer
   x = 1,298.33