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Finding the Fourth Proportional to 391.18, 587.05 and 147.72

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Solution

The fourth proportional to 391.18, 587.05 and 147.72 is: 221.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.18 : 587.05 = 147.72 : x
  2. Step 2: Convert to fraction form
    391.18/587.05 = 147.72/x
  3. Step 3: Cross multiply
    391.18x = 587.05 × 147.72
  4. Step 4: Simplify right side
    391.18x = 86,719.03
  5. Step 5: Solve for x
    x = 86,719.03/391.18
  6. Step 6: Final answer
    x = 221.69

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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.