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Finding the Fourth Proportional to 638.55, 880.88 and 491.13

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Solution

The fourth proportional to 638.55, 880.88 and 491.13 is: 677.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.55 : 880.88 = 491.13 : x
  2. Step 2: Convert to fraction form
    638.55/880.88 = 491.13/x
  3. Step 3: Cross multiply
    638.55x = 880.88 × 491.13
  4. Step 4: Simplify right side
    638.55x = 432,624.14
  5. Step 5: Solve for x
    x = 432,624.14/638.55
  6. Step 6: Final answer
    x = 677.51

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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.