Finding the Fourth Proportional to 1,298.86, 1,792.56 and 767.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.86 : 1,792.56 = 767.91 : x
2. Step 2: Convert to fraction form
   1,298.86/1,792.56 = 767.91/x
3. Step 3: Cross multiply
   1,298.86x = 1,792.56 × 767.91
4. Step 4: Simplify right side
   1,298.86x = 1,376,524.75
5. Step 5: Solve for x
   x = 1,376,524.75/1,298.86
6. Step 6: Final answer
   x = 1,059.79