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Finding the Fourth Proportional to 684.77, 1,024.57 and 420.28

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Solution

The fourth proportional to 684.77, 1,024.57 and 420.28 is: 628.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.77 : 1,024.57 = 420.28 : x
  2. Step 2: Convert to fraction form
    684.77/1,024.57 = 420.28/x
  3. Step 3: Cross multiply
    684.77x = 1,024.57 × 420.28
  4. Step 4: Simplify right side
    684.77x = 430,606.28
  5. Step 5: Solve for x
    x = 430,606.28/684.77
  6. Step 6: Final answer
    x = 628.83

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.