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Finding the Fourth Proportional to 420.16, 629.04 and 317.20

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Solution

The fourth proportional to 420.16, 629.04 and 317.20 is: 474.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.16 : 629.04 = 317.20 : x
  2. Step 2: Convert to fraction form
    420.16/629.04 = 317.20/x
  3. Step 3: Cross multiply
    420.16x = 629.04 × 317.20
  4. Step 4: Simplify right side
    420.16x = 199,531.49
  5. Step 5: Solve for x
    x = 199,531.49/420.16
  6. Step 6: Final answer
    x = 474.89

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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.