Finding the Fourth Proportional to 1,043.69, 1,564.72 and 991.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,043.69 : 1,564.72 = 991.74 : x
2. Step 2: Convert to fraction form
   1,043.69/1,564.72 = 991.74/x
3. Step 3: Cross multiply
   1,043.69x = 1,564.72 × 991.74
4. Step 4: Simplify right side
   1,043.69x = 1,551,798.80
5. Step 5: Solve for x
   x = 1,551,798.80/1,043.69
6. Step 6: Final answer
   x = 1,486.85