Finding the Fourth Proportional to 1,045.48, 1,566.72 and 428.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,045.48 : 1,566.72 = 428.52 : x
2. Step 2: Convert to fraction form
   1,045.48/1,566.72 = 428.52/x
3. Step 3: Cross multiply
   1,045.48x = 1,566.72 × 428.52
4. Step 4: Simplify right side
   1,045.48x = 671,370.85
5. Step 5: Solve for x
   x = 671,370.85/1,045.48
6. Step 6: Final answer
   x = 642.17