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Finding the Fourth Proportional to 787.21, 1,086.37 and 455.75

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Solution

The fourth proportional to 787.21, 1,086.37 and 455.75 is: 628.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.21 : 1,086.37 = 455.75 : x
  2. Step 2: Convert to fraction form
    787.21/1,086.37 = 455.75/x
  3. Step 3: Cross multiply
    787.21x = 1,086.37 × 455.75
  4. Step 4: Simplify right side
    787.21x = 495,113.13
  5. Step 5: Solve for x
    x = 495,113.13/787.21
  6. Step 6: Final answer
    x = 628.95

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.