Finding the Fourth Proportional to 1,422.64, 2,131.53 and 772.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.64 : 2,131.53 = 772.21 : x
2. Step 2: Convert to fraction form
   1,422.64/2,131.53 = 772.21/x
3. Step 3: Cross multiply
   1,422.64x = 2,131.53 × 772.21
4. Step 4: Simplify right side
   1,422.64x = 1,645,988.78
5. Step 5: Solve for x
   x = 1,645,988.78/1,422.64
6. Step 6: Final answer
   x = 1,157.00