Finding the Fourth Proportional to 42,741.60, 64,088.88 and 13,151.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,741.60 : 64,088.88 = 13,151.20 : x
2. Step 2: Convert to fraction form
   42,741.60/64,088.88 = 13,151.20/x
3. Step 3: Cross multiply
   42,741.60x = 64,088.88 × 13,151.20
4. Step 4: Simplify right side
   42,741.60x = 842,845,678.66
5. Step 5: Solve for x
   x = 842,845,678.66/42,741.60
6. Step 6: Final answer
   x = 19,719.56