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Finding the Fourth Proportional to 640.90, 886.17 and 558.89

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Solution

The fourth proportional to 640.90, 886.17 and 558.89 is: 772.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.90 : 886.17 = 558.89 : x
  2. Step 2: Convert to fraction form
    640.90/886.17 = 558.89/x
  3. Step 3: Cross multiply
    640.90x = 886.17 × 558.89
  4. Step 4: Simplify right side
    640.90x = 495,271.55
  5. Step 5: Solve for x
    x = 495,271.55/640.90
  6. Step 6: Final answer
    x = 772.78

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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.