Finding the Fourth Proportional to 1,561.71, 2,341.34 and 867.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.71 : 2,341.34 = 867.78 : x
2. Step 2: Convert to fraction form
   1,561.71/2,341.34 = 867.78/x
3. Step 3: Cross multiply
   1,561.71x = 2,341.34 × 867.78
4. Step 4: Simplify right side
   1,561.71x = 2,031,763.69
5. Step 5: Solve for x
   x = 2,031,763.69/1,561.71
6. Step 6: Final answer
   x = 1,300.99