Finding the Fourth Proportional to 1,019.64, 1,406.88 and 870.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.64 : 1,406.88 = 870.82 : x
2. Step 2: Convert to fraction form
   1,019.64/1,406.88 = 870.82/x
3. Step 3: Cross multiply
   1,019.64x = 1,406.88 × 870.82
4. Step 4: Simplify right side
   1,019.64x = 1,225,139.24
5. Step 5: Solve for x
   x = 1,225,139.24/1,019.64
6. Step 6: Final answer
   x = 1,201.54