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Finding the Fourth Proportional to 664.72, 917.40 and 455.11

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Solution

The fourth proportional to 664.72, 917.40 and 455.11 is: 628.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.72 : 917.40 = 455.11 : x
  2. Step 2: Convert to fraction form
    664.72/917.40 = 455.11/x
  3. Step 3: Cross multiply
    664.72x = 917.40 × 455.11
  4. Step 4: Simplify right side
    664.72x = 417,517.91
  5. Step 5: Solve for x
    x = 417,517.91/664.72
  6. Step 6: Final answer
    x = 628.11

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.