Finding the Fourth Proportional to 2,607.57, 3,907.98 and 1,989

Step by Step Solution

1. Step 1: Write the proportion equation
   2,607.57 : 3,907.98 = 1,989 : x
2. Step 2: Convert to fraction form
   2,607.57/3,907.98 = 1,989/x
3. Step 3: Cross multiply
   2,607.57x = 3,907.98 × 1,989
4. Step 4: Simplify right side
   2,607.57x = 7,772,972.22
5. Step 5: Solve for x
   x = 7,772,972.22/2,607.57
6. Step 6: Final answer
   x = 2,980.93