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Finding the Fourth Proportional to 390.20, 537.38 and 381.70

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Solution

The fourth proportional to 390.20, 537.38 and 381.70 is: 525.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.20 : 537.38 = 381.70 : x
  2. Step 2: Convert to fraction form
    390.20/537.38 = 381.70/x
  3. Step 3: Cross multiply
    390.20x = 537.38 × 381.70
  4. Step 4: Simplify right side
    390.20x = 205,115.26
  5. Step 5: Solve for x
    x = 205,115.26/390.20
  6. Step 6: Final answer
    x = 525.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.