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Finding the Fourth Proportional to 391.38, 587.08 and 317.91

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Solution

The fourth proportional to 391.38, 587.08 and 317.91 is: 476.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.38 : 587.08 = 317.91 : x
  2. Step 2: Convert to fraction form
    391.38/587.08 = 317.91/x
  3. Step 3: Cross multiply
    391.38x = 587.08 × 317.91
  4. Step 4: Simplify right side
    391.38x = 186,640.31
  5. Step 5: Solve for x
    x = 186,640.31/391.38
  6. Step 6: Final answer
    x = 476.87

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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.