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Finding the Fourth Proportional to 420.83, 631.23 and 318.31

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Solution

The fourth proportional to 420.83, 631.23 and 318.31 is: 477.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.83 : 631.23 = 318.31 : x
  2. Step 2: Convert to fraction form
    420.83/631.23 = 318.31/x
  3. Step 3: Cross multiply
    420.83x = 631.23 × 318.31
  4. Step 4: Simplify right side
    420.83x = 200,926.82
  5. Step 5: Solve for x
    x = 200,926.82/420.83
  6. Step 6: Final answer
    x = 477.45

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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.