Finding the Fourth Proportional to 42,715.80, 64,074.71 and 13,133.90

Step by Step Solution

1. Step 1: Write the proportion equation
   42,715.80 : 64,074.71 = 13,133.90 : x
2. Step 2: Convert to fraction form
   42,715.80/64,074.71 = 13,133.90/x
3. Step 3: Cross multiply
   42,715.80x = 64,074.71 × 13,133.90
4. Step 4: Simplify right side
   42,715.80x = 841,551,026.69
5. Step 5: Solve for x
   x = 841,551,026.69/42,715.80
6. Step 6: Final answer
   x = 19,701.17