Finding the Third Proportional to 156,931 and 221,090

Step by Step Solution

1. Step 1: Write the proportion equation
   156,931 : 221,090 = 221,090 : x
2. Step 2: Convert to fraction form
   156,931/221,090 = 221,090/x
3. Step 3: Cross multiply
   156,931x = 221,090 × 221,090
4. Step 4: Simplify right side
   156,931x = 48,880,788,100
5. Step 5: Solve for x
   x = 48,880,788,100/156,931
6. Step 6: Final answer
   x = 311,479.49