Finding the Fourth Proportional to 42,979.55, 64,482.53 and 20,518.89

Step by Step Solution

1. Step 1: Write the proportion equation
   42,979.55 : 64,482.53 = 20,518.89 : x
2. Step 2: Convert to fraction form
   42,979.55/64,482.53 = 20,518.89/x
3. Step 3: Cross multiply
   42,979.55x = 64,482.53 × 20,518.89
4. Step 4: Simplify right side
   42,979.55x = 1,323,109,837.40
5. Step 5: Solve for x
   x = 1,323,109,837.40/42,979.55
6. Step 6: Final answer
   x = 30,784.64