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Finding the Fourth Proportional to 521.60, 780.64 and 392.96

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Solution

The fourth proportional to 521.60, 780.64 and 392.96 is: 588.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.60 : 780.64 = 392.96 : x
  2. Step 2: Convert to fraction form
    521.60/780.64 = 392.96/x
  3. Step 3: Cross multiply
    521.60x = 780.64 × 392.96
  4. Step 4: Simplify right side
    521.60x = 306,760.29
  5. Step 5: Solve for x
    x = 306,760.29/521.60
  6. Step 6: Final answer
    x = 588.11

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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.