Finding the Third Proportional to 858,276 and 1,261,139

Step by Step Solution

1. Step 1: Write the proportion equation
   858,276 : 1,261,139 = 1,261,139 : x
2. Step 2: Convert to fraction form
   858,276/1,261,139 = 1,261,139/x
3. Step 3: Cross multiply
   858,276x = 1,261,139 × 1,261,139
4. Step 4: Simplify right side
   858,276x = 1,590,471,577,321
5. Step 5: Solve for x
   x = 1,590,471,577,321/858,276
6. Step 6: Final answer
   x = 1,853,100.37