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Finding the Fourth Proportional to 665.72, 919.13 and 429.78

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Solution

The fourth proportional to 665.72, 919.13 and 429.78 is: 593.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.72 : 919.13 = 429.78 : x
  2. Step 2: Convert to fraction form
    665.72/919.13 = 429.78/x
  3. Step 3: Cross multiply
    665.72x = 919.13 × 429.78
  4. Step 4: Simplify right side
    665.72x = 395,018.10
  5. Step 5: Solve for x
    x = 395,018.10/665.72
  6. Step 6: Final answer
    x = 593.37

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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.