Finding the Fourth Proportional to 1,421.69, 1,962.06 and 862.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.69 : 1,962.06 = 862.55 : x
2. Step 2: Convert to fraction form
   1,421.69/1,962.06 = 862.55/x
3. Step 3: Cross multiply
   1,421.69x = 1,962.06 × 862.55
4. Step 4: Simplify right side
   1,421.69x = 1,692,365.04
5. Step 5: Solve for x
   x = 1,692,365.04/1,421.69
6. Step 6: Final answer
   x = 1,190.39