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Finding the Fourth Proportional to 381.78, 526.89 and 215.99

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Solution

The fourth proportional to 381.78, 526.89 and 215.99 is: 298.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.78 : 526.89 = 215.99 : x
  2. Step 2: Convert to fraction form
    381.78/526.89 = 215.99/x
  3. Step 3: Cross multiply
    381.78x = 526.89 × 215.99
  4. Step 4: Simplify right side
    381.78x = 113,802.97
  5. Step 5: Solve for x
    x = 113,802.97/381.78
  6. Step 6: Final answer
    x = 298.09

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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.