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Finding the Fourth Proportional to 781.75, 1,171.88 and 288.05

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Solution

The fourth proportional to 781.75, 1,171.88 and 288.05 is: 431.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.75 : 1,171.88 = 288.05 : x
  2. Step 2: Convert to fraction form
    781.75/1,171.88 = 288.05/x
  3. Step 3: Cross multiply
    781.75x = 1,171.88 × 288.05
  4. Step 4: Simplify right side
    781.75x = 337,553.81
  5. Step 5: Solve for x
    x = 337,553.81/781.75
  6. Step 6: Final answer
    x = 431.79

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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.