Finding the Third Proportional to 1,242 and 1,978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,242 : 1,978.50 = 1,978.50 : x
2. Step 2: Convert to fraction form
   1,242/1,978.50 = 1,978.50/x
3. Step 3: Cross multiply
   1,242x = 1,978.50 × 1,978.50
4. Step 4: Simplify right side
   1,242x = 3,914,462.25
5. Step 5: Solve for x
   x = 3,914,462.25/1,242
6. Step 6: Final answer
   x = 3,151.74