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Finding the Fourth Proportional to 431.00, 649.68 and 405.91

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Solution

The fourth proportional to 431.00, 649.68 and 405.91 is: 611.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.00 : 649.68 = 405.91 : x
  2. Step 2: Convert to fraction form
    431.00/649.68 = 405.91/x
  3. Step 3: Cross multiply
    431.00x = 649.68 × 405.91
  4. Step 4: Simplify right side
    431.00x = 263,710.90
  5. Step 5: Solve for x
    x = 263,710.90/431.00
  6. Step 6: Final answer
    x = 611.86

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.