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Finding the Fourth Proportional to 678.38, 936.58 and 520.71

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Solution

The fourth proportional to 678.38, 936.58 and 520.71 is: 718.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.38 : 936.58 = 520.71 : x
  2. Step 2: Convert to fraction form
    678.38/936.58 = 520.71/x
  3. Step 3: Cross multiply
    678.38x = 936.58 × 520.71
  4. Step 4: Simplify right side
    678.38x = 487,688.77
  5. Step 5: Solve for x
    x = 487,688.77/678.38
  6. Step 6: Final answer
    x = 718.90

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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.