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Finding the Fourth Proportional to 781.85, 1,171.87 and 521.54

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Solution

The fourth proportional to 781.85, 1,171.87 and 521.54 is: 781.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.85 : 1,171.87 = 521.54 : x
  2. Step 2: Convert to fraction form
    781.85/1,171.87 = 521.54/x
  3. Step 3: Cross multiply
    781.85x = 1,171.87 × 521.54
  4. Step 4: Simplify right side
    781.85x = 611,174.31
  5. Step 5: Solve for x
    x = 611,174.31/781.85
  6. Step 6: Final answer
    x = 781.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.