Finding the Fourth Proportional to 1,401.69, 2,102.86 and 427.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.69 : 2,102.86 = 427.79 : x
2. Step 2: Convert to fraction form
   1,401.69/2,102.86 = 427.79/x
3. Step 3: Cross multiply
   1,401.69x = 2,102.86 × 427.79
4. Step 4: Simplify right side
   1,401.69x = 899,583.55
5. Step 5: Solve for x
   x = 899,583.55/1,401.69
6. Step 6: Final answer
   x = 641.78