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Finding the Fourth Proportional to 391.05, 586.71 and 171.72

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Solution

The fourth proportional to 391.05, 586.71 and 171.72 is: 257.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.05 : 586.71 = 171.72 : x
  2. Step 2: Convert to fraction form
    391.05/586.71 = 171.72/x
  3. Step 3: Cross multiply
    391.05x = 586.71 × 171.72
  4. Step 4: Simplify right side
    391.05x = 100,749.84
  5. Step 5: Solve for x
    x = 100,749.84/391.05
  6. Step 6: Final answer
    x = 257.64

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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.