Finding the Fourth Proportional to 1,982.31, 2,970.78 and 1,288.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,982.31 : 2,970.78 = 1,288.62 : x
2. Step 2: Convert to fraction form
   1,982.31/2,970.78 = 1,288.62/x
3. Step 3: Cross multiply
   1,982.31x = 2,970.78 × 1,288.62
4. Step 4: Simplify right side
   1,982.31x = 3,828,206.52
5. Step 5: Solve for x
   x = 3,828,206.52/1,982.31
6. Step 6: Final answer
   x = 1,931.18