Finding the Fourth Proportional to 1,036.89, 1,554.52 and 420.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,036.89 : 1,554.52 = 420.75 : x
2. Step 2: Convert to fraction form
   1,036.89/1,554.52 = 420.75/x
3. Step 3: Cross multiply
   1,036.89x = 1,554.52 × 420.75
4. Step 4: Simplify right side
   1,036.89x = 654,064.29
5. Step 5: Solve for x
   x = 654,064.29/1,036.89
6. Step 6: Final answer
   x = 630.79