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Finding the Fourth Proportional to 626.50, 864.85 and 393.78

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Solution

The fourth proportional to 626.50, 864.85 and 393.78 is: 543.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.50 : 864.85 = 393.78 : x
  2. Step 2: Convert to fraction form
    626.50/864.85 = 393.78/x
  3. Step 3: Cross multiply
    626.50x = 864.85 × 393.78
  4. Step 4: Simplify right side
    626.50x = 340,560.63
  5. Step 5: Solve for x
    x = 340,560.63/626.50
  6. Step 6: Final answer
    x = 543.59

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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.