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Finding the Fourth Proportional to 521.99, 720.09 and 381.87

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Solution

The fourth proportional to 521.99, 720.09 and 381.87 is: 526.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.99 : 720.09 = 381.87 : x
  2. Step 2: Convert to fraction form
    521.99/720.09 = 381.87/x
  3. Step 3: Cross multiply
    521.99x = 720.09 × 381.87
  4. Step 4: Simplify right side
    521.99x = 274,980.77
  5. Step 5: Solve for x
    x = 274,980.77/521.99
  6. Step 6: Final answer
    x = 526.79

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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.