Finding the Fourth Proportional to 1,987.78, 2,979.52 and 1,013.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,987.78 : 2,979.52 = 1,013.95 : x
2. Step 2: Convert to fraction form
   1,987.78/2,979.52 = 1,013.95/x
3. Step 3: Cross multiply
   1,987.78x = 2,979.52 × 1,013.95
4. Step 4: Simplify right side
   1,987.78x = 3,021,084.30
5. Step 5: Solve for x
   x = 3,021,084.30/1,987.78
6. Step 6: Final answer
   x = 1,519.83