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Finding the Fourth Proportional to 640.48, 883.56 and 553

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Solution

The fourth proportional to 640.48, 883.56 and 553 is: 762.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.48 : 883.56 = 553 : x
  2. Step 2: Convert to fraction form
    640.48/883.56 = 553/x
  3. Step 3: Cross multiply
    640.48x = 883.56 × 553
  4. Step 4: Simplify right side
    640.48x = 488,608.68
  5. Step 5: Solve for x
    x = 488,608.68/640.48
  6. Step 6: Final answer
    x = 762.88

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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.