Finding the Third Proportional to 1,245.38 and 1,387.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.38 : 1,387.76 = 1,387.76 : x
2. Step 2: Convert to fraction form
   1,245.38/1,387.76 = 1,387.76/x
3. Step 3: Cross multiply
   1,245.38x = 1,387.76 × 1,387.76
4. Step 4: Simplify right side
   1,245.38x = 1,925,871.75
5. Step 5: Solve for x
   x = 1,925,871.75/1,245.38
6. Step 6: Final answer
   x = 1,546.42