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Finding the Fourth Proportional to 657.72, 906.39 and 640.71

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Solution

The fourth proportional to 657.72, 906.39 and 640.71 is: 882.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.72 : 906.39 = 640.71 : x
  2. Step 2: Convert to fraction form
    657.72/906.39 = 640.71/x
  3. Step 3: Cross multiply
    657.72x = 906.39 × 640.71
  4. Step 4: Simplify right side
    657.72x = 580,733.14
  5. Step 5: Solve for x
    x = 580,733.14/657.72
  6. Step 6: Final answer
    x = 882.95

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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.