Finding the Fourth Proportional to 1,561.95, 2,155.76 and 1,188.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.95 : 2,155.76 = 1,188.33 : x
2. Step 2: Convert to fraction form
   1,561.95/2,155.76 = 1,188.33/x
3. Step 3: Cross multiply
   1,561.95x = 2,155.76 × 1,188.33
4. Step 4: Simplify right side
   1,561.95x = 2,561,748.34
5. Step 5: Solve for x
   x = 2,561,748.34/1,561.95
6. Step 6: Final answer
   x = 1,640.10