Finding the Fourth Proportional to 1,300.72, 1,949.70 and 991.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,300.72 : 1,949.70 = 991.90 : x
2. Step 2: Convert to fraction form
   1,300.72/1,949.70 = 991.90/x
3. Step 3: Cross multiply
   1,300.72x = 1,949.70 × 991.90
4. Step 4: Simplify right side
   1,300.72x = 1,933,907.43
5. Step 5: Solve for x
   x = 1,933,907.43/1,300.72
6. Step 6: Final answer
   x = 1,486.80