Finding the Fourth Proportional to 1,086.21, 1,499.76 and 667.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.21 : 1,499.76 = 667.13 : x
2. Step 2: Convert to fraction form
   1,086.21/1,499.76 = 667.13/x
3. Step 3: Cross multiply
   1,086.21x = 1,499.76 × 667.13
4. Step 4: Simplify right side
   1,086.21x = 1,000,538.64
5. Step 5: Solve for x
   x = 1,000,538.64/1,086.21
6. Step 6: Final answer
   x = 921.13