Finding the Fourth Proportional to 42,976.79, 64,468.29 and 17,991.71

Step by Step Solution

1. Step 1: Write the proportion equation
   42,976.79 : 64,468.29 = 17,991.71 : x
2. Step 2: Convert to fraction form
   42,976.79/64,468.29 = 17,991.71/x
3. Step 3: Cross multiply
   42,976.79x = 64,468.29 × 17,991.71
4. Step 4: Simplify right side
   42,976.79x = 1,159,894,777.88
5. Step 5: Solve for x
   x = 1,159,894,777.88/42,976.79
6. Step 6: Final answer
   x = 26,988.86