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Finding the Fourth Proportional to 391.14, 585.18 and 309.12

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Solution

The fourth proportional to 391.14, 585.18 and 309.12 is: 462.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.14 : 585.18 = 309.12 : x
  2. Step 2: Convert to fraction form
    391.14/585.18 = 309.12/x
  3. Step 3: Cross multiply
    391.14x = 585.18 × 309.12
  4. Step 4: Simplify right side
    391.14x = 180,890.84
  5. Step 5: Solve for x
    x = 180,890.84/391.14
  6. Step 6: Final answer
    x = 462.47

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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.