Finding the Fourth Proportional to 42,860.85, 64,308.18 and 13,281

Step by Step Solution

1. Step 1: Write the proportion equation
   42,860.85 : 64,308.18 = 13,281 : x
2. Step 2: Convert to fraction form
   42,860.85/64,308.18 = 13,281/x
3. Step 3: Cross multiply
   42,860.85x = 64,308.18 × 13,281
4. Step 4: Simplify right side
   42,860.85x = 854,076,938.58
5. Step 5: Solve for x
   x = 854,076,938.58/42,860.85
6. Step 6: Final answer
   x = 19,926.74