Finding the Fourth Proportional to 1,533.15, 2,115.83 and 870.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,533.15 : 2,115.83 = 870.21 : x
2. Step 2: Convert to fraction form
   1,533.15/2,115.83 = 870.21/x
3. Step 3: Cross multiply
   1,533.15x = 2,115.83 × 870.21
4. Step 4: Simplify right side
   1,533.15x = 1,841,218.60
5. Step 5: Solve for x
   x = 1,841,218.60/1,533.15
6. Step 6: Final answer
   x = 1,200.94