Finding the Fourth Proportional to 42,970.30, 64,458.52 and 17,985.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,970.30 : 64,458.52 = 17,985.20 : x
2. Step 2: Convert to fraction form
   42,970.30/64,458.52 = 17,985.20/x
3. Step 3: Cross multiply
   42,970.30x = 64,458.52 × 17,985.20
4. Step 4: Simplify right side
   42,970.30x = 1,159,299,373.90
5. Step 5: Solve for x
   x = 1,159,299,373.90/42,970.30
6. Step 6: Final answer
   x = 26,979.08