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Finding the Fourth Proportional to 391.70, 587.55 and 343.70

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Solution

The fourth proportional to 391.70, 587.55 and 343.70 is: 515.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.70 : 587.55 = 343.70 : x
  2. Step 2: Convert to fraction form
    391.70/587.55 = 343.70/x
  3. Step 3: Cross multiply
    391.70x = 587.55 × 343.70
  4. Step 4: Simplify right side
    391.70x = 201,940.94
  5. Step 5: Solve for x
    x = 201,940.94/391.70
  6. Step 6: Final answer
    x = 515.55

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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.