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Finding the Fourth Proportional to 638.99, 881.81 and 616.91

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Solution

The fourth proportional to 638.99, 881.81 and 616.91 is: 851.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.99 : 881.81 = 616.91 : x
  2. Step 2: Convert to fraction form
    638.99/881.81 = 616.91/x
  3. Step 3: Cross multiply
    638.99x = 881.81 × 616.91
  4. Step 4: Simplify right side
    638.99x = 543,998.84
  5. Step 5: Solve for x
    x = 543,998.84/638.99
  6. Step 6: Final answer
    x = 851.35

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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.