Finding the Fourth Proportional to 42,688.36, 64,071.32 and 21,643.08

Step by Step Solution

1. Step 1: Write the proportion equation
   42,688.36 : 64,071.32 = 21,643.08 : x
2. Step 2: Convert to fraction form
   42,688.36/64,071.32 = 21,643.08/x
3. Step 3: Cross multiply
   42,688.36x = 64,071.32 × 21,643.08
4. Step 4: Simplify right side
   42,688.36x = 1,386,700,704.47
5. Step 5: Solve for x
   x = 1,386,700,704.47/42,688.36
6. Step 6: Final answer
   x = 32,484.28