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Finding the Fourth Proportional to 630.47, 869.14 and 420.57

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Solution

The fourth proportional to 630.47, 869.14 and 420.57 is: 579.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.47 : 869.14 = 420.57 : x
  2. Step 2: Convert to fraction form
    630.47/869.14 = 420.57/x
  3. Step 3: Cross multiply
    630.47x = 869.14 × 420.57
  4. Step 4: Simplify right side
    630.47x = 365,533.47
  5. Step 5: Solve for x
    x = 365,533.47/630.47
  6. Step 6: Final answer
    x = 579.78

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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.