Finding the Fourth Proportional to 1,407.38, 2,111.67 and 830.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.38 : 2,111.67 = 830.25 : x
2. Step 2: Convert to fraction form
   1,407.38/2,111.67 = 830.25/x
3. Step 3: Cross multiply
   1,407.38x = 2,111.67 × 830.25
4. Step 4: Simplify right side
   1,407.38x = 1,753,214.02
5. Step 5: Solve for x
   x = 1,753,214.02/1,407.38
6. Step 6: Final answer
   x = 1,245.73