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Finding the Fourth Proportional to 626.79, 864.81 and 390.63

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Solution

The fourth proportional to 626.79, 864.81 and 390.63 is: 538.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.79 : 864.81 = 390.63 : x
  2. Step 2: Convert to fraction form
    626.79/864.81 = 390.63/x
  3. Step 3: Cross multiply
    626.79x = 864.81 × 390.63
  4. Step 4: Simplify right side
    626.79x = 337,820.73
  5. Step 5: Solve for x
    x = 337,820.73/626.79
  6. Step 6: Final answer
    x = 538.97

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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.