Finding the Fourth Proportional to 1,407.31, 2,111.58 and 542.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.31 : 2,111.58 = 542.23 : x
2. Step 2: Convert to fraction form
   1,407.31/2,111.58 = 542.23/x
3. Step 3: Cross multiply
   1,407.31x = 2,111.58 × 542.23
4. Step 4: Simplify right side
   1,407.31x = 1,144,962.02
5. Step 5: Solve for x
   x = 1,144,962.02/1,407.31
6. Step 6: Final answer
   x = 813.58