Finding the Fourth Proportional to 1,561.94, 2,155.91 and 972.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.94 : 2,155.91 = 972.13 : x
2. Step 2: Convert to fraction form
   1,561.94/2,155.91 = 972.13/x
3. Step 3: Cross multiply
   1,561.94x = 2,155.91 × 972.13
4. Step 4: Simplify right side
   1,561.94x = 2,095,809.15
5. Step 5: Solve for x
   x = 2,095,809.15/1,561.94
6. Step 6: Final answer
   x = 1,341.80