Finding the Fourth Proportional to 1,667.15, 2,300.72 and 921.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,667.15 : 2,300.72 = 921.12 : x
2. Step 2: Convert to fraction form
   1,667.15/2,300.72 = 921.12/x
3. Step 3: Cross multiply
   1,667.15x = 2,300.72 × 921.12
4. Step 4: Simplify right side
   1,667.15x = 2,119,234.60
5. Step 5: Solve for x
   x = 2,119,234.60/1,667.15
6. Step 6: Final answer
   x = 1,271.17