Finding the Fourth Proportional to 42,987.58, 64,451.96 and 21,886.79

Step by Step Solution

1. Step 1: Write the proportion equation
   42,987.58 : 64,451.96 = 21,886.79 : x
2. Step 2: Convert to fraction form
   42,987.58/64,451.96 = 21,886.79/x
3. Step 3: Cross multiply
   42,987.58x = 64,451.96 × 21,886.79
4. Step 4: Simplify right side
   42,987.58x = 1,410,646,513.61
5. Step 5: Solve for x
   x = 1,410,646,513.61/42,987.58
6. Step 6: Final answer
   x = 32,815.21