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Finding the Fourth Proportional to 649.08, 972.90 and 405.72

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Solution

The fourth proportional to 649.08, 972.90 and 405.72 is: 608.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.08 : 972.90 = 405.72 : x
  2. Step 2: Convert to fraction form
    649.08/972.90 = 405.72/x
  3. Step 3: Cross multiply
    649.08x = 972.90 × 405.72
  4. Step 4: Simplify right side
    649.08x = 394,724.99
  5. Step 5: Solve for x
    x = 394,724.99/649.08
  6. Step 6: Final answer
    x = 608.13

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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.