Finding the Fourth Proportional to 1,686.72, 2,327.76 and 988.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,686.72 : 2,327.76 = 988.10 : x
2. Step 2: Convert to fraction form
   1,686.72/2,327.76 = 988.10/x
3. Step 3: Cross multiply
   1,686.72x = 2,327.76 × 988.10
4. Step 4: Simplify right side
   1,686.72x = 2,300,043.08
5. Step 5: Solve for x
   x = 2,300,043.08/1,686.72
6. Step 6: Final answer
   x = 1,363.62