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Finding the Fourth Proportional to 521.78, 780.37 and 392.38

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Solution

The fourth proportional to 521.78, 780.37 and 392.38 is: 586.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.78 : 780.37 = 392.38 : x
  2. Step 2: Convert to fraction form
    521.78/780.37 = 392.38/x
  3. Step 3: Cross multiply
    521.78x = 780.37 × 392.38
  4. Step 4: Simplify right side
    521.78x = 306,198.65
  5. Step 5: Solve for x
    x = 306,198.65/521.78
  6. Step 6: Final answer
    x = 586.84

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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.