Finding the Fourth Proportional to 1,987.60, 2,980.72 and 892.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,987.60 : 2,980.72 = 892.96 : x
2. Step 2: Convert to fraction form
   1,987.60/2,980.72 = 892.96/x
3. Step 3: Cross multiply
   1,987.60x = 2,980.72 × 892.96
4. Step 4: Simplify right side
   1,987.60x = 2,661,663.73
5. Step 5: Solve for x
   x = 2,661,663.73/1,987.60
6. Step 6: Final answer
   x = 1,339.13