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Finding the Fourth Proportional to 626.78, 864.78 and 378.20

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Solution

The fourth proportional to 626.78, 864.78 and 378.20 is: 521.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.78 : 864.78 = 378.20 : x
  2. Step 2: Convert to fraction form
    626.78/864.78 = 378.20/x
  3. Step 3: Cross multiply
    626.78x = 864.78 × 378.20
  4. Step 4: Simplify right side
    626.78x = 327,059.80
  5. Step 5: Solve for x
    x = 327,059.80/626.78
  6. Step 6: Final answer
    x = 521.81

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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.