Finding the Fourth Proportional to 1,015.69, 1,522.15 and 430.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.69 : 1,522.15 = 430.21 : x
2. Step 2: Convert to fraction form
   1,015.69/1,522.15 = 430.21/x
3. Step 3: Cross multiply
   1,015.69x = 1,522.15 × 430.21
4. Step 4: Simplify right side
   1,015.69x = 654,844.15
5. Step 5: Solve for x
   x = 654,844.15/1,015.69
6. Step 6: Final answer
   x = 644.73