Finding the Fourth Proportional to 42,978.81, 64,459.80 and 21,625.80

Step by Step Solution

1. Step 1: Write the proportion equation
   42,978.81 : 64,459.80 = 21,625.80 : x
2. Step 2: Convert to fraction form
   42,978.81/64,459.80 = 21,625.80/x
3. Step 3: Cross multiply
   42,978.81x = 64,459.80 × 21,625.80
4. Step 4: Simplify right side
   42,978.81x = 1,393,994,742.84
5. Step 5: Solve for x
   x = 1,393,994,742.84/42,978.81
6. Step 6: Final answer
   x = 32,434.47