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Finding the Fourth Proportional to 420.36, 629.61 and 317.70

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Solution

The fourth proportional to 420.36, 629.61 and 317.70 is: 475.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.36 : 629.61 = 317.70 : x
  2. Step 2: Convert to fraction form
    420.36/629.61 = 317.70/x
  3. Step 3: Cross multiply
    420.36x = 629.61 × 317.70
  4. Step 4: Simplify right side
    420.36x = 200,027.10
  5. Step 5: Solve for x
    x = 200,027.10/420.36
  6. Step 6: Final answer
    x = 475.85

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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.