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Finding the Fourth Proportional to 420.61, 629.73 and 317.57

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Solution

The fourth proportional to 420.61, 629.73 and 317.57 is: 475.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.61 : 629.73 = 317.57 : x
  2. Step 2: Convert to fraction form
    420.61/629.73 = 317.57/x
  3. Step 3: Cross multiply
    420.61x = 629.73 × 317.57
  4. Step 4: Simplify right side
    420.61x = 199,983.36
  5. Step 5: Solve for x
    x = 199,983.36/420.61
  6. Step 6: Final answer
    x = 475.46

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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.