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Finding the Fourth Proportional to 771.75, 1,158.17 and 387

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Solution

The fourth proportional to 771.75, 1,158.17 and 387 is: 580.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.75 : 1,158.17 = 387 : x
  2. Step 2: Convert to fraction form
    771.75/1,158.17 = 387/x
  3. Step 3: Cross multiply
    771.75x = 1,158.17 × 387
  4. Step 4: Simplify right side
    771.75x = 448,209.86
  5. Step 5: Solve for x
    x = 448,209.86/771.75
  6. Step 6: Final answer
    x = 580.77

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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.