Finding the Fourth Proportional to 1,561.69, 2,155.56 and 971.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.69 : 2,155.56 = 971.88 : x
2. Step 2: Convert to fraction form
   1,561.69/2,155.56 = 971.88/x
3. Step 3: Cross multiply
   1,561.69x = 2,155.56 × 971.88
4. Step 4: Simplify right side
   1,561.69x = 2,094,945.65
5. Step 5: Solve for x
   x = 2,094,945.65/1,561.69
6. Step 6: Final answer
   x = 1,341.46