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Finding the Fourth Proportional to 378.99, 522.39 and 285.57

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Solution

The fourth proportional to 378.99, 522.39 and 285.57 is: 393.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.99 : 522.39 = 285.57 : x
  2. Step 2: Convert to fraction form
    378.99/522.39 = 285.57/x
  3. Step 3: Cross multiply
    378.99x = 522.39 × 285.57
  4. Step 4: Simplify right side
    378.99x = 149,178.91
  5. Step 5: Solve for x
    x = 149,178.91/378.99
  6. Step 6: Final answer
    x = 393.62

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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.