Finding the Fourth Proportional to 35,978.21, 53,934.65 and 12,591.89

Step by Step Solution

1. Step 1: Write the proportion equation
   35,978.21 : 53,934.65 = 12,591.89 : x
2. Step 2: Convert to fraction form
   35,978.21/53,934.65 = 12,591.89/x
3. Step 3: Cross multiply
   35,978.21x = 53,934.65 × 12,591.89
4. Step 4: Simplify right side
   35,978.21x = 679,139,117.03
5. Step 5: Solve for x
   x = 679,139,117.03/35,978.21
6. Step 6: Final answer
   x = 18,876.40