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Finding the Fourth Proportional to 669.64, 1,005.36 and 425.56

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Solution

The fourth proportional to 669.64, 1,005.36 and 425.56 is: 638.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.64 : 1,005.36 = 425.56 : x
  2. Step 2: Convert to fraction form
    669.64/1,005.36 = 425.56/x
  3. Step 3: Cross multiply
    669.64x = 1,005.36 × 425.56
  4. Step 4: Simplify right side
    669.64x = 427,841.00
  5. Step 5: Solve for x
    x = 427,841.00/669.64
  6. Step 6: Final answer
    x = 638.91

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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.