Finding the Fourth Proportional to 66,196.40, 91,372.28 and 42,387.20

Step by Step Solution

1. Step 1: Write the proportion equation
   66,196.40 : 91,372.28 = 42,387.20 : x
2. Step 2: Convert to fraction form
   66,196.40/91,372.28 = 42,387.20/x
3. Step 3: Cross multiply
   66,196.40x = 91,372.28 × 42,387.20
4. Step 4: Simplify right side
   66,196.40x = 3,873,015,106.82
5. Step 5: Solve for x
   x = 3,873,015,106.82/66,196.40
6. Step 6: Final answer
   x = 58,507.94