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Finding the Fourth Proportional to 458.80, 688.20 and 431.47

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Solution

The fourth proportional to 458.80, 688.20 and 431.47 is: 647.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.80 : 688.20 = 431.47 : x
  2. Step 2: Convert to fraction form
    458.80/688.20 = 431.47/x
  3. Step 3: Cross multiply
    458.80x = 688.20 × 431.47
  4. Step 4: Simplify right side
    458.80x = 296,937.65
  5. Step 5: Solve for x
    x = 296,937.65/458.80
  6. Step 6: Final answer
    x = 647.21

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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.