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Finding the Fourth Proportional to 391.29, 587.15 and 147.79

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Solution

The fourth proportional to 391.29, 587.15 and 147.79 is: 221.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.29 : 587.15 = 147.79 : x
  2. Step 2: Convert to fraction form
    391.29/587.15 = 147.79/x
  3. Step 3: Cross multiply
    391.29x = 587.15 × 147.79
  4. Step 4: Simplify right side
    391.29x = 86,774.90
  5. Step 5: Solve for x
    x = 86,774.90/391.29
  6. Step 6: Final answer
    x = 221.77

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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.