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Finding the Fourth Proportional to 678.96, 938.16 and 663.84

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Solution

The fourth proportional to 678.96, 938.16 and 663.84 is: 917.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.96 : 938.16 = 663.84 : x
  2. Step 2: Convert to fraction form
    678.96/938.16 = 663.84/x
  3. Step 3: Cross multiply
    678.96x = 938.16 × 663.84
  4. Step 4: Simplify right side
    678.96x = 622,788.13
  5. Step 5: Solve for x
    x = 622,788.13/678.96
  6. Step 6: Final answer
    x = 917.27

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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.