Finding the Fourth Proportional to 1,298.79, 1,939.89 and 1,175.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.79 : 1,939.89 = 1,175.21 : x
2. Step 2: Convert to fraction form
   1,298.79/1,939.89 = 1,175.21/x
3. Step 3: Cross multiply
   1,298.79x = 1,939.89 × 1,175.21
4. Step 4: Simplify right side
   1,298.79x = 2,279,768.43
5. Step 5: Solve for x
   x = 2,279,768.43/1,298.79
6. Step 6: Final answer
   x = 1,755.30