Finding the Fourth Proportional to 1,667.79, 2,301.53 and 921.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,667.79 : 2,301.53 = 921.78 : x
2. Step 2: Convert to fraction form
   1,667.79/2,301.53 = 921.78/x
3. Step 3: Cross multiply
   1,667.79x = 2,301.53 × 921.78
4. Step 4: Simplify right side
   1,667.79x = 2,121,499.71
5. Step 5: Solve for x
   x = 2,121,499.71/1,667.79
6. Step 6: Final answer
   x = 1,272.04