Finding the Third Proportional to 598.78 and 1,288.69

Step by Step Solution

1. Step 1: Write the proportion equation
   598.78 : 1,288.69 = 1,288.69 : x
2. Step 2: Convert to fraction form
   598.78/1,288.69 = 1,288.69/x
3. Step 3: Cross multiply
   598.78x = 1,288.69 × 1,288.69
4. Step 4: Simplify right side
   598.78x = 1,660,715.47
5. Step 5: Solve for x
   x = 1,660,715.47/598.78
6. Step 6: Final answer
   x = 2,773.49