Finding the Fourth Proportional to 1,392.10, 1,953.80 and 1,392.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.10 : 1,953.80 = 1,392.10 : x
2. Step 2: Convert to fraction form
   1,392.10/1,953.80 = 1,392.10/x
3. Step 3: Cross multiply
   1,392.10x = 1,953.80 × 1,392.10
4. Step 4: Simplify right side
   1,392.10x = 2,719,884.98
5. Step 5: Solve for x
   x = 2,719,884.98/1,392.10
6. Step 6: Final answer
   x = 1,953.80