Finding the Fourth Proportional to 42,820.25, 64,231.18 and 11,655.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,820.25 : 64,231.18 = 11,655.50 : x
2. Step 2: Convert to fraction form
   42,820.25/64,231.18 = 11,655.50/x
3. Step 3: Cross multiply
   42,820.25x = 64,231.18 × 11,655.50
4. Step 4: Simplify right side
   42,820.25x = 748,646,168.20
5. Step 5: Solve for x
   x = 748,646,168.20/42,820.25
6. Step 6: Final answer
   x = 17,483.46