Finding the Fourth Proportional to 1,983.78, 2,976.12 and 667.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,983.78 : 2,976.12 = 667.50 : x
2. Step 2: Convert to fraction form
   1,983.78/2,976.12 = 667.50/x
3. Step 3: Cross multiply
   1,983.78x = 2,976.12 × 667.50
4. Step 4: Simplify right side
   1,983.78x = 1,986,548.07
5. Step 5: Solve for x
   x = 1,986,548.07/1,983.78
6. Step 6: Final answer
   x = 1,001.40