Finding the Fourth Proportional to 1,408.30, 2,112.72 and 830.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.30 : 2,112.72 = 830.50 : x
2. Step 2: Convert to fraction form
   1,408.30/2,112.72 = 830.50/x
3. Step 3: Cross multiply
   1,408.30x = 2,112.72 × 830.50
4. Step 4: Simplify right side
   1,408.30x = 1,754,613.96
5. Step 5: Solve for x
   x = 1,754,613.96/1,408.30
6. Step 6: Final answer
   x = 1,245.91