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Finding the Fourth Proportional to 626.72, 864.38 and 390.81

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Solution

The fourth proportional to 626.72, 864.38 and 390.81 is: 539.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.72 : 864.38 = 390.81 : x
  2. Step 2: Convert to fraction form
    626.72/864.38 = 390.81/x
  3. Step 3: Cross multiply
    626.72x = 864.38 × 390.81
  4. Step 4: Simplify right side
    626.72x = 337,806.39
  5. Step 5: Solve for x
    x = 337,806.39/626.72
  6. Step 6: Final answer
    x = 539.01

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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.