Finding the Fourth Proportional to 1,429.60, 1,972.56 and 870.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.60 : 1,972.56 = 870.24 : x
2. Step 2: Convert to fraction form
   1,429.60/1,972.56 = 870.24/x
3. Step 3: Cross multiply
   1,429.60x = 1,972.56 × 870.24
4. Step 4: Simplify right side
   1,429.60x = 1,716,600.61
5. Step 5: Solve for x
   x = 1,716,600.61/1,429.60
6. Step 6: Final answer
   x = 1,200.76