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Finding the Fourth Proportional to 648.40, 972.96 and 405.04

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Solution

The fourth proportional to 648.40, 972.96 and 405.04 is: 607.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.40 : 972.96 = 405.04 : x
  2. Step 2: Convert to fraction form
    648.40/972.96 = 405.04/x
  3. Step 3: Cross multiply
    648.40x = 972.96 × 405.04
  4. Step 4: Simplify right side
    648.40x = 394,087.72
  5. Step 5: Solve for x
    x = 394,087.72/648.40
  6. Step 6: Final answer
    x = 607.78

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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.