Finding the Fourth Proportional to 42,681.71, 64,020.14 and 13,099.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,681.71 : 64,020.14 = 13,099.50 : x
2. Step 2: Convert to fraction form
   42,681.71/64,020.14 = 13,099.50/x
3. Step 3: Cross multiply
   42,681.71x = 64,020.14 × 13,099.50
4. Step 4: Simplify right side
   42,681.71x = 838,631,758.43
5. Step 5: Solve for x
   x = 838,631,758.43/42,681.71
6. Step 6: Final answer
   x = 19,648.51