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Finding the Fourth Proportional to 669.72, 1,005 and 345.32

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Solution

The fourth proportional to 669.72, 1,005 and 345.32 is: 518.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.72 : 1,005 = 345.32 : x
  2. Step 2: Convert to fraction form
    669.72/1,005 = 345.32/x
  3. Step 3: Cross multiply
    669.72x = 1,005 × 345.32
  4. Step 4: Simplify right side
    669.72x = 347,046.60
  5. Step 5: Solve for x
    x = 347,046.60/669.72
  6. Step 6: Final answer
    x = 518.20

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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.