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Finding the Fourth Proportional to 665.28, 918.72 and 628.92

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Solution

The fourth proportional to 665.28, 918.72 and 628.92 is: 868.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.28 : 918.72 = 628.92 : x
  2. Step 2: Convert to fraction form
    665.28/918.72 = 628.92/x
  3. Step 3: Cross multiply
    665.28x = 918.72 × 628.92
  4. Step 4: Simplify right side
    665.28x = 577,801.38
  5. Step 5: Solve for x
    x = 577,801.38/665.28
  6. Step 6: Final answer
    x = 868.51

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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.