Finding the Fourth Proportional to 1,113.50, 1,667.50 and 840.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,113.50 : 1,667.50 = 840.13 : x
2. Step 2: Convert to fraction form
   1,113.50/1,667.50 = 840.13/x
3. Step 3: Cross multiply
   1,113.50x = 1,667.50 × 840.13
4. Step 4: Simplify right side
   1,113.50x = 1,400,910.51
5. Step 5: Solve for x
   x = 1,400,910.51/1,113.50
6. Step 6: Final answer
   x = 1,258.11