Finding the Fourth Proportional to 42,770.61, 64,151.78 and 13,180.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,770.61 : 64,151.78 = 13,180.50 : x
2. Step 2: Convert to fraction form
   42,770.61/64,151.78 = 13,180.50/x
3. Step 3: Cross multiply
   42,770.61x = 64,151.78 × 13,180.50
4. Step 4: Simplify right side
   42,770.61x = 845,552,536.29
5. Step 5: Solve for x
   x = 845,552,536.29/42,770.61
6. Step 6: Final answer
   x = 19,769.48