Finding the Fourth Proportional to 1,967.50, 2,715.28 and 1,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,967.50 : 2,715.28 = 1,139.50 : x
2. Step 2: Convert to fraction form
   1,967.50/2,715.28 = 1,139.50/x
3. Step 3: Cross multiply
   1,967.50x = 2,715.28 × 1,139.50
4. Step 4: Simplify right side
   1,967.50x = 3,094,061.56
5. Step 5: Solve for x
   x = 3,094,061.56/1,967.50
6. Step 6: Final answer
   x = 1,572.59