Finding the Fourth Proportional to 1,985.60, 2,978.72 and 889.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.60 : 2,978.72 = 889.96 : x
2. Step 2: Convert to fraction form
   1,985.60/2,978.72 = 889.96/x
3. Step 3: Cross multiply
   1,985.60x = 2,978.72 × 889.96
4. Step 4: Simplify right side
   1,985.60x = 2,650,941.65
5. Step 5: Solve for x
   x = 2,650,941.65/1,985.60
6. Step 6: Final answer
   x = 1,335.08