Finding the Fourth Proportional to 1,561.64, 2,155.35 and 1,002.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.64 : 2,155.35 = 1,002.81 : x
2. Step 2: Convert to fraction form
   1,561.64/2,155.35 = 1,002.81/x
3. Step 3: Cross multiply
   1,561.64x = 2,155.35 × 1,002.81
4. Step 4: Simplify right side
   1,561.64x = 2,161,406.25
5. Step 5: Solve for x
   x = 2,161,406.25/1,561.64
6. Step 6: Final answer
   x = 1,384.07