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Finding the Fourth Proportional to 646.60, 891.36 and 557.68

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Solution

The fourth proportional to 646.60, 891.36 and 557.68 is: 768.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.60 : 891.36 = 557.68 : x
  2. Step 2: Convert to fraction form
    646.60/891.36 = 557.68/x
  3. Step 3: Cross multiply
    646.60x = 891.36 × 557.68
  4. Step 4: Simplify right side
    646.60x = 497,093.64
  5. Step 5: Solve for x
    x = 497,093.64/646.60
  6. Step 6: Final answer
    x = 768.78

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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.